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

24 Oct '14

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

3 2

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

24 Oct '14

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

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

23 Oct '14

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

1 0

unused parameter warning
by Kevin Molcard 23 Oct '14

23 Oct '14

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

1 0

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

22 Oct '14

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

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Flyweight: wrapping shared_ptr
by Akim Demaille 22 Oct '14

22 Oct '14

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

3 11

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

21 Oct '14

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

1 0

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

21 Oct '14

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

7 17

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

20 Oct '14

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

1 0

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

20 Oct '14

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

6 6

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

17 Oct '14

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

1 0

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

16 Oct '14

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

2 1

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

16 Oct '14

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

1 0

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

16 Oct '14

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

1 1

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

14 Oct '14

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

1 0

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

13 Oct '14

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

1 0

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

13 Oct '14

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

1 0

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

10 Oct '14

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

1 0

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

10 Oct '14

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

2 1

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

10 Oct '14

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

2 1

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

10 Oct '14

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

3 20

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

10 Oct '14

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

2 2

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

10 Oct '14

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

2 1

[Boost.Polygon] Bug in polygon_set_data, or are my expectations wrong?
by Patrick J. LoPresti 09 Oct '14

09 Oct '14

I have just submitted a bug report: https://svn.boost.org/trac/boost/ticket/10642 ...but I am wondering if the bug is in my understanding rather than in Boost.Polygon. The test case is very simple, so I am appending it to this message. My question is, should I expect polygon_set_data<int> to scramble such a simple figure? It almost looks like some (but not all) of the coordinates are being snapped to multiples of 2. Or something. Note that doubling all of the coordinates avoids the bug. Assuming it is a bug (?) Thanks! - Pat #include <boost/polygon/polygon.hpp> #include <iostream> #include <cstdlib> namespace bp = boost::polygon; using namespace bp::operators; typedef bp::polygon_set_data<int> PolygonSet; typedef bp::polygon_data<PolygonSet::coordinate_type> Polygon; typedef bp::polygon_traits<Polygon>::point_type Point; int main(int argc, char *argv[]) { // Small figure with a little hole. Area should be 32. const Point points[] = { Point(0,0), Point(6,0), Point(6,4), Point(4,6), Point(0,6), Point(0,0), Point(4,4), Point(5,4) }; Polygon poly1(&points[0], &points[sizeof(points)/sizeof(points[0])]); PolygonSet ps1; ps1 += poly1; std::cout << "poly1 area == " << area(poly1) << "\n"; // Boost.Polygon says the area of ps1 is 30. That is because its internal // representation is wrong, as you can confirm by manually // examining the result of ps1.get() or ps1.get_trapezoids(). std::cout << "ps1 area == " << area(ps1) << "\n"; // Doubling the coordinates avoids the bug. Polygon poly2(poly1); scale_up(poly2, 2); PolygonSet ps2; ps2 += poly2; std::cout << "poly2 area == " << area(poly2) << "\n"; std::cout << "ps2 area == " << area(ps2) << "\n"; assert(area(poly2) == area(ps2)); assert(area(poly1) == area(ps1)); }

1 0

[polygon] Incorrect output from get_trapezoids(..., HORIZONTAL)
by Patrick J. LoPresti 08 Oct '14

08 Oct '14

I apologize for sending this to the mailing list, but when I tried to file a bug report via Trac, it said "Trac thinks your submission might be Spam. To prove otherwise please provide a response to the following"... And then there was no "following". Please let me know if there is a better forum to report this sort of issue. I am using Boost 1.56. The following program uses boost::polygon to slice up a figure (with a "hole" cut out of it) into horizontal trapezoids. The output I get is: Output: polygon (4 3) (4 0) (0 0) (0 3) (4 3) ...which is clearly wrong. I am pretty sure my code is correct, because if I replace bg::HORIZONTAL with bg::VERTICAL, I get the correct output of a bunch of vertical trapezoids. For my application, I really want horizontal traps. I suppose I can just swap x and y on input and output... But this seemed worth reporting. Thanks. - Pat #include <boost/polygon/polygon.hpp> #include <iostream> namespace bp = boost::polygon; typedef bp::polygon_set_data<int> PolygonSet; typedef bp::polygon_data<PolygonSet::coordinate_type> Polygon; typedef bp::polygon_traits<Polygon>::point_type Point; std::ostream & operator<<(std::ostream &os, const Point &pt) { return os << "(" << bp::x(pt) << " " << bp::y(pt) << ")"; } std::ostream & operator<<(std::ostream &os, const Polygon &poly) { os << "polygon "; for (Polygon::iterator_type p = poly.begin() ; p != poly.end() ; ++p) os << " " << *p; return os; } std::ostream & operator<<(std::ostream &os, const PolygonSet &ps) { std::vector<Polygon> temp; ps.get(temp); os << "polygonset "; for (std::vector<Polygon>::const_iterator p = temp.begin() ; p != temp.end() ; ++p) os << " " << *p; return os; } int main(int argc, char *argv[]) { const Point points[] = { Point(2,0), Point(4,0), Point(4,3), Point(0,3), Point(0,0), Point(2,0), Point(2,1), Point(1,1), Point(1,2), Point(3,2), Point(3,1), Point(2,1) }; Polygon poly; bp::set_points(poly, &points[0], &points[sizeof(points)/sizeof(points[0])]); std::cout << "Input: " << poly << "\n"; PolygonSet ps; ps.insert(poly); std::cout << "ps = " << ps << "\n"; std::vector<Polygon> traps; // Note: bp::VERTICAL works fine bp::get_trapezoids(traps, ps, bp::HORIZONTAL); std::cout << "Output:\n"; for (std::vector<Polygon>::const_iterator p = traps.begin() ; p != traps.end() ; ++p) std::cout << *p << "\n"; }

2 2

program_options: Make PO not eat argc
by Florian Lindner 08 Oct '14

08 Oct '14

Hello, I have a couple of libraries (MPI, petsc) that also consume my applications argc and argv, which is parsed with boost::program_options before. po seems to eat up argv, i.e. removes all items that it handles. Can I disable that behavior somehow so that po does not touch argc/argv. Or do I need to recreate it, e.g. using collect_unrecognized? Thanks, Florian

2 2

program_options: How to best model two/three pos args
by Florian Lindner 08 Oct '14

08 Oct '14

Hello, my application has positional arguments like that: Run tests : ./app test ConfigurationName PathToSrc Run server : ./app server ParticipantName ConfigurationName Print XML reference: ./app xml Linewidth It has three (if first in [test, server]) or two (if first in [xml]) positional arguments. How to model and test this best using boost? I could add three options and declare them as positional arguments, named like "first", "second", "third". I could also use just one positional argument like: po::positional_options_description pos_dec; pos_dec.add("positionals", 3); and test the resulting vector. What do you think? Thanks, Florian

2 1

MSM to diagram
by Robert Bielik 08 Oct '14

08 Oct '14

Hi all, I want to use MSM in an application, however, for design documentation purposes I'd like to be able to express the state machine in a diagram. And preferably going the route from C++ code -> graphical diagram (i.e. not from UML -> C++ code). Has anyone looked at that, or know of resources on how to accomplish this ? TIA /Robert

1 0

[general] Advice from Bjarne Stroustrup
by legalize+jeeves＠mail.xmission.com 06 Oct '14

06 Oct '14

[Please do not mail me a copy of your followup] At the end of each chapter in "The C++ Programming Language", 4th edition, Bjarne Stroustrup has a list of advice. I found the advice very helpful and decided that the advice should be online somewhere. Initially I put this together as a PPT presentation, but oh my lord, it was too long. Instead, I made a page in my user space on the cppreference.com wiki: <http://en.cppreference.com/w/User:Legalize/Advice_from_Bjarne_Stroustrup> This let me link to other pages on the wiki describing specific language features where possible. Hopefully you will find it useful. -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

2 1

NT² eand Boost.SIMD release 3.1
by Joel FALCOU 06 Oct '14

06 Oct '14

NT2 is a Matlab inspired, high-level API for scientific computation in C++. Boost.SIMD is a candidate library for inclusion in Boost dealing with the portable encpsulation of SIMD instructions sets. This following releases updates NT2 and Boost.SIMD libraries to version 3.1 This new release of NT2 and Boost.SIMD focused on fixing performance issues and add some new support for architecture and parallel algorithms. The main new features include: - Linear Algebra functions can now use GPGPU through the MAGMA library whenever possible. - Reduction and Scan operations now works with more shared memory back-end - Altivec support is now complete for the VMX ISA We wish to thanks Ian Masliah for his work on MAGMA, Antoine Tran Tan for the shared memory support and Pierre Esterie participation to the Altivec ISA completion. Special thanks to Tim Blenchmann and khegeman for their help and patch submisisons throughout this development. The release Changelog is here : https://github.com/MetaScale/nt2/releases/tag/3.1.0 The files can be download from : http://nt2.metascale.org/downloads/ The Documentation (in progress) is here : http://nt2.metascale.org/doc/html/index.html **Next release announcment** This release is the last C++03 compliant version of both NT2 and Boost.SIMD. The next release - 4.0 - will be C++11 only. The new minimal version of supported compilers will be : - g++ 4.6 - Microsoft Visual Studio 12 (2013) - clang 3.4 - icc 12.1 The main reason for this change is to be able to properly fix the compile-time issue that one may experience. It'll also allow us to use some C++11 feature to simplify or streamline some of the user interface. * The NT2 Team

1 0

[bimap] Look ups on the vector_of collection type
by Arindam Mukherjee 05 Oct '14

05 Oct '14

Would it make sense to define a bimap like this: boost::bimap< boost::bimaps::set_of<std::string>, boost::bimaps::vector_of<std::string>> mymap; And then make the right view (vector_of) more amenable to lookups by performing a sort followed by a binary search on it? Thanks.

1 0

Flat multi set operation costs
by Paolo Bolzoni 03 Oct '14

03 Oct '14

Dear list, In a project of mine I am using a sorted vector as a multimap. The point was that insert, delete and retrieval operations arrived in batches (lots of inserts, lots of retrieval, lots of deletes...) so I essentially saved time sorting the vector when a new kind of operation arrived. I recently noticed boost has the flat multiset implementation, so I was wondering do it follows the same idea? If it does I would be nice to kick-out some code and use the library for ease of maintenance. Your faithfully, Paolo

2 1

boost python wrapping class with getter/setter with const string& arg and return type
by MM 03 Oct '14

03 Oct '14

Hi class C { public: const std::string& get_name() const; void set_name(const std::string&); private: std::string name_; }; given this class C, how would I expose it to python with the class property name? class_<C>("C"). .add_property("name", &C::get_name, &C::set_name); with the proper includes as in the tutorial, it fails to compile. MM

1 0

[Test] Global Fixtures
by Mauricio Carneiro 03 Oct '14

03 Oct '14

I am trying to use global fixtures in my tests but I may be misinterpreting the documentations. The following toy example doesn't work : #include <boost/test/unit_test.hpp> struct TruthFixture { int x = 3; int f (int a) { return a + 3; } }; BOOST_GLOBAL_FIXTURE( TruthFixture ) BOOST_AUTO_TEST_CASE(test_variable) { printf("x = %d\n", x); } BOOST_AUTO_TEST_CASE(test_function) { printf("f(2) = %d\n", f(2)); } the error message I get is the following: test/test.cpp:14:22: error: use of undeclared identifier 'x'; did you mean 'TruthFixture::x'? printf("x = %d\n", x); ^ TruthFixture::x test/test.cpp:4:7: note: 'TruthFixture::x' declared here int x = 3; ^ test/test.cpp:14:22: error: invalid use of non-static data member 'x' printf("x = %d\n", x); ^ test/test.cpp:18:25: error: use of undeclared identifier 'f'; did you mean 'TruthFixture::f'? printf("f(2) = %d\n", f(2)); ^ TruthFixture::f test/test.cpp:6:7: note: 'TruthFixture::f' declared here int f (int a) { ^ test/test.cpp:18:25: error: call to non-static member function without an object argument printf("f(2) = %d\n", f(2)); ^ 4 errors generated. clearly the BOOST_GLOBAL_FIXTURE declaration is not doing anything. But if I drop the global fixture declaration and revert to the per function declaration, it works: #include <boost/test/unit_test.hpp> struct TruthFixture { int x = 3; int f (int a) { return a + 3; } }; BOOST_FIXTURE_TEST_CASE(test_variable, TruthFixture) { printf("x = %d\n", x); } BOOST_FIXTURE_TEST_CASE(test_function, TruthFixture) { printf("f(2) = %d\n", f(2)); } then everything works perfectly as intended. Any input on what I am doing wrong with the *global* fixture declaration? Thank you! Mauricio Carneiro, Ph.D. http://www.broadinstitute.org/~carneiro/

2 1

[Boost] [DateTime] dividing a time_period in N time_periods
by Pablo Madoery 02 Oct '14

02 Oct '14

Hi, I want to make a method which divides a time_period in N time periods, something like this: list<time_period> splitTimePeriod(time_period timePeriod, int n); I actually have made it and although it seems to work it results very inefficient regarding the time it took to divide a large time_period. The method I did is this: list<time_period> splitTimePeriod(time_period timePeriod, int n) { double secsTime = dateTime::diffSeconds(timePeriod.end(), timePeriod.begin()); // tiempo en segundos de cada período de tiempo double ti = secsTime / n; list<time_period> timePeriods; // tiempo de comienzo del primer período de tiempo ptime tpBegin = timePeriod.begin(); // tiempo de fin del último período de tiempo ptime tpLastEnd = timePeriod.end(); for (int i = 0; i < n; i++) { int tUnits = ti * time_duration::ticks_per_second(); // tiempo de comienzo del siguiente período de tiempo ptime tpNextBegin = dateTime::increment(tpBegin, tUnits); // tiempo de fin del período de tiempo ptime tpEnd; if (i == n - 1) { tpEnd = tpLastEnd; } else { tpEnd = dateTime::decrement(tpNextBegin, 1); // guarda para evitar que por cuestiones // de redondeo, el tiempo final de un período // sea mayor que el pasado inicialmente // como argumento de entrada if (tpEnd > tpLastEnd) { tpEnd = tpLastEnd; } } time_period p(tpBegin, tpEnd); // se inserta período de tiempo en la lista timePeriods.push_back(p); // se actualiza el comienzo del siguiente período de tiempo tpBegin = tpNextBegin; } return timePeriods; } Other methods I use are these: double diffSeconds(const ptime &dateA, const ptime &dateB) { time_duration diff = dateA - dateB; return diff.total_seconds(); } ptime increment(const ptime &date, int n) { time_iterator it(date, dateTime::unit); for (int i = 0; i < n; i++) { ++it; } return *it; } ptime decrement(const ptime &date, int n) { time_iterator it(date, dateTime::unit); for (int i = 0; i < n; i++) { --it; } return *it; } const time_duration unit = microseconds(1); ################################################# The question is: is there a better way to accomplish this?

3 6

[mpl] struct definition and mpl sequence in one shot?
by Adam Romanek 01 Oct '14

01 Oct '14

Hi! I have a problem and I'm not sure how to approach it. Currently my code looks like this: struct Definition { typedef boost::mpl::int_<5> A; typedef boost::mpl::int_<3> B; typedef boost::mpl::int_<6> C; typedef boost::mpl::int_<1> D; typedef boost::mpl::vector<A, B, C, D> Seq; }; Here, the number N in mpl::int_< N > denotes some arbitrary decimal number. Then some other code calculates the sum of these numbers up to the type defined by "key", e.g. for Definition::D, the sum is 5 + 3 + 6 (A + B + C). This needs to be done at compile-time. That's why I use mpl::vector and some appropriate meta-programming. I'm wondering whether it would be possible to provide such struct definition without the need to repeat type names in the mpl::vector for Seq type. In other words, I'd probably need a bunch of macros which would allow me to write code like this: struct Definition { FIELD(A, 5); FIELD(B, 3); FIELD(C, 6); FIELD(D, 1); GEN_SEQ() // if needed }; And then Definition::A would still refer to boost::mpl::int_<5>, or would at least allow me to access the boost::mpl::int_<5> somehow, and Definition::Seq would give me the appropriate MPL sequence. Of couse this is just my imagination. The code might look different, I'm just looking for options. Thanks in advance. Adam Romanek

1 0

[Build] -finline-functions no longer supported in clang 3.5
by Mauricio Carneiro 01 Oct '14

01 Oct '14

Hi all, turns out clang 3.5 is no longer supporting <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…> -finline- <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…> functions <http://llvm.org/klaus/clang/commit/6590426aeb5275ec33dac2877f9349bbbb2d4b2e…>, which it claims never did anything anyway, so this is their way to take it out of usage. My release builds (which are done solely through boost build) automatically add this parameter to the compilation command line, and thus is now failing (since I use -Werror). Is there a way to modify the "release" variant not to use that line anymore? Also, is there a way to extend the command line parameters that the release variant will use? Thank you, Mauricio Carneiro, Ph.D. http://www.broadinstitute.org/~carneiro/

1 0

boost::log native syslog sink.
by svante karlsson 01 Oct '14

01 Oct '14

I'm using ubuntu 14.04 with the included boost 1.54 and I'm trying to set up a syslog sink. I've cut this from the samples and added "ident". void init_syslog() { boost::shared_ptr< boost::log::core > core = boost::log::core::get(); // Create a backend boost::shared_ptr< sinks::syslog_backend > backend(new sinks::syslog_backend( keywords::facility = sinks::syslog::local0, keywords::use_impl = sinks::syslog::native, keywords::ident = "mqtt-proxy" )); // Set the straightforward level translator for the "Severity" attribute of type int backend->set_severity_mapper(sinks::syslog::direct_severity_mapping< int >("Severity")); // Wrap it into the frontend and register in the core. // The backend requires synchronization in the frontend. core->add_sink(boost::make_shared< sink_t >(backend)); } The logs end up in syslog but I cant prefix those by program name (and processnumber ) - I've expected the logs to be marked as 'mqtt-proxy' I get logs like Sep 29 03:47:40 ubuntu : ad569c57-780a-431b-bde3-7ede49e7c77f, bridge create but what I would like is similar to Sep 29 03:47:40 ubuntu mqtt-proxy: ad569c57-780a-431b-bde3-7ede49e7c77f, bridge create Am I missing something or is ident not supported? /svante

1 0

[Threads] and OpenMP
by Stephan Menzel 01 Oct '14

01 Oct '14

Hi all, I would like to ask around about a strategy on how to tacke the following threading problem: I am maintaining a boost intensive portable C++ client-server application and recently have included a highly complex 3rd party algorithm into my application that does CPU intense stuff. Long running stuff. Often in the range of days. While at the same time being heavy in OpenMP usage. Now of course requirements are that the user has to be able to cancel this. The algorithm runs in a boost threads controlled background thread. Now I began to place interruption points throughout the 3rd party code but soon had to realize that a lot of CPU time is being handled in OpenMP threaded code regions. So the question is: How can I more or less gracefully shut this down? How do interruption points work in an omp parallel for loop? Do I have a chance at all? My constraints here are a bit forgiving. Given the complexity of the 3rd party code I have already accepted the notion that this is gonna be a memleak monster. Luckily, there's no disk or other hardware access so I'm ready to live with a certain amount of mem not being cleaned up. Yet the backend thread communicates with the spawning class by calling a mutexed callback when it's ready so the user knows it's cancelled. This is protected by a boost mutex as well. And juding from the horrible threading "clogs" that I observed in my first trials I suppose this is gonna be a problem as well. And input is appreciated. And yes, I am aware that this is gonna be an ugly mess. Cheers, Stephan

3 3

Re: [Boost-users] choosing source ip on multihomed computer (Bjorn Reese)
by David Frank 01 Oct '14

01 Oct '14

I did, here is my relevant code segment, but the destination still shows that I sent from another ip than what I set here: tcp::resolver resolver(fIo_service); tcp::resolver::query query(tcp::v4(), host, port); tcp::resolver::iterator iterator = resolver.resolve(query); fpSocket = new tcp::socket(fIo_service); if (fpSocket == nullptr) return ; fpSocket->open(boost::asio::ip::tcp::v4()); fpSocket->bind(boost::asio::ip::tcp::endpoint(boost::asio::ip::address::from_string("<ip>"), 0)); boost::system::error_code errcode; boost::asio::connect(*fpSocket, iterator, errcode); On Tuesday, September 30, 2014 12:00 PM, "boost-users-request(a)lists.boost.org" <boost-users-request(a)lists.boost.org> wrote: Send Boost-users mailing list submissions to boost-users(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.boost.org/mailman/listinfo.cgi/boost-users or, via email, send a message with subject or body 'help' to boost-users-request(a)lists.boost.org You can reach the person managing the list at boost-users-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost-users digest..." Today's Topics: 1. Re: choosing source ip on multihomed computer (Bjorn Reese) 2. Re: [Threads] and OpenMP (Bjorn Reese) ---------------------------------------------------------------------- Message: 1 Date: Tue, 30 Sep 2014 15:58:37 +0200 From: Bjorn Reese <breese(a)mail1.stofanet.dk> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] choosing source ip on multihomed computer Message-ID: <542AB70D.6060807(a)mail1.stofanet.dk> Content-Type: text/plain; charset=windows-1252; format=flowed On 09/30/2014 03:04 PM, David Frank wrote: > I'm wondering how to make boost::asio::connect(<socket>, ...) > connect from the source interface/ip address I choose on a multihomed > computer. Call bind() before connect(). ------------------------------ Message: 2 Date: Tue, 30 Sep 2014 15:59:43 +0200 From: Bjorn Reese <breese(a)mail1.stofanet.dk> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Threads] and OpenMP Message-ID: <542AB74F.4010303(a)mail1.stofanet.dk> Content-Type: text/plain; charset=windows-1252; format=flowed On 09/30/2014 11:24 AM, Stephan Menzel wrote: > So the question is: How can I more or less gracefully shut this down? > How do interruption points work in an omp parallel for loop? Do I have a > chance at all? One approach is to execute the tasks in a separate process. The process can easily be killed, and it takes care of the memory leaks. ------------------------------ Subject: Digest Footer _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ------------------------------ End of Boost-users Digest, Vol 3932, Issue 2 ********************************************

1 0

[bimap] Mapping a set into itself
by Arindam Mukherjee 30 Sep '14

30 Sep '14

Is there a way to represent a mapping from a set to itself using boost::bimap? Regards, Arindam

1 0

choosing source ip on multihomed computer
by David Frank 30 Sep '14

30 Sep '14

Hi, I'm wondering how to make boost::asio::connect(<socket>, ...) connect from the source interface/ip address I choose on a multihomed computer. Thanks, Dave

2 1

[serialization] serialize type-erasure
by oswin krause 30 Sep '14

30 Sep '14

Hi list, i am currently trying to serialize a type-erasure, but i am not sure how this should be done exactly. Before boost 1.56 we used the polymorphic archives and a base class to implement serialization, but since they are broken in 1.56 and a few users are nagging me (plus i can't compile the library myself any more after a mandatory upgrade...), i have to get it right. my setup looks like this class ErasureBase{ .... }; template<class T> class Erasure{ public: Erasure (T& foo):m_foo(foo){} template<class Archive> void serialize(Archive & ar, const unsigned int){ ar & m_foo; } private: T& m_foo; }; class MyClass{ public: template<class T> MyClass(T& foo):m_wrapper(new Erasure<T>(foo)){} template<class Archive> void serialize(Archive & ar, const unsigned int){ ar & *m_wrapper; } private: boost::scoped_ptr<ErasureBase> m_wrapper; }; in the usage of MyClass i assume that serialisation/deserialisation is only to be called on constructed objects of type MyClass, therefore i do not need capabilities to deserialize from pointers. The question is: how do I tell the archive which Erasure<T> exist? The solutions in the tutorial pages only look at the cases where Erasure<T> is serialized directly or where it is known which classes are to be serialized (and i don't assume my users to know which Erasure<T> are instantiated...). If there exists a solution for this: is the solution also stable wrt the order of registration of classes? Best, Oswin The ques

1 1

[multi_index] Couple of questions on multi-index containers
by Aaron Levy 29 Sep '14

29 Sep '14

If I erase elements in a multi_index_container, how are iterators invalidated? 1. For other than random_access index, only iterators to the deleted element? 2. For random_access index, potentially any iterator? What are the data structures used internally for this container and its indexes. -- Aaron Levy aaron.levy(a)yandex.com

4 5

[msm] & typeerasure / any
by Raj Sambasivan 28 Sep '14

28 Sep '14

HI Boost-users/christophe, I'm trying to make use of type erasure for fsm based on suggestion from an earlier mail thread http://boost.2283326.n4.nabble.com/msm-access-to-root-fsm-td4649632.html but hitting compilation errors. Can you pls help? while the any works as expected for push back e.g for vector (bottom of email) it doesnt work for MSM.. *Doesn't Work for MSM:* BOOST_TYPE_ERASURE_MEMBER((has_process_event), process_event, 1) typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; struct AnyFSM { AnyFSM(any_fsm afsm_) : _afsm(afsm_) {} void process(Event1& e) { _afsm.process_event(e); } any_fsm _afsm; }; TestFSM test; test.start(); AnyFSM(test); test.process(Event1()); *error:* *test.cpp:47:43: **error: **'Event1' does not refer to a value* typedef any<has_process_event<HandledEnum(Event1 const &)>, _self&> any_fsm; *Works for vector:* BOOST_TYPE_ERASURE_MEMBER((has_push_back), push_back, 1) typedef any<has_push_back<void(int)>, _self&> any_container; void append_many(any_container container) { for(int i = 0; i < 10; ++i) container.push_back(i); } struct AnyContainer { AnyContainer(any_container cont_) : _cont(cont_) {} void append() {append_many(_cont); } any_container _cont; }; AnyContainer m(v); m.append(); for(auto i : v) { std::cout << i << std::endl; } Thanks -Raj

1 1

[Log] [ASIO with ssl] windows service crash on windows server 2008
by Pritesh Acharya 27 Sep '14

27 Sep '14

Details: OS: Windows Server 2008 SP2 Boost 1.56.0 (shared library) OpenSSL: Win32OpenSSL-1_0_1i I have a windows service application written in C++. As a minimal test case, I have created a small demo code to show the problem. The service just log some information to a file and does nothing. The same code has no problem in my Development machine(windows7) and window Server 2003. Also on Windows Server 2008, when the service is run as LocalSystem privilege, it crashes, but when run as Administrator it works. Additionally, when I remove the asio ssl header from the code, it works. or when I remove the log header, it works. The problem seems to be related to when ASIO ssl and LOG are used together. Below I've included 1. Code 2. User Mode Crash dump 3. Call Stack obtained from running Crash Dump *1. Code:* *#include <boost/log/trivial.hpp>* *#include <boost/log/sources/severity_logger.hpp>* *#include <boost/asio/ssl.hpp>* *#include <windows.h>* *#include <stdio.h>* *#define SLEEP_TIME 5000* *#define LOGFILE "C:\\AASSLInstaller_D_56\\memstatus.txt"* *SERVICE_STATUS ServiceStatus; * *SERVICE_STATUS_HANDLE hStatus; * *void ServiceMain(int argc, char** argv); * *void ControlHandler(DWORD request); * *int InitService();* *int WriteToLog(char* str)* *{* * FILE* log;* * log = fopen(LOGFILE, "a+");* * if (log == NULL)* * return -1;* * fprintf(log, "%s\n", str);* * fclose(log);* * return 0;* *}* *//void ThreadFunction()* *//{* *// WriteToLog("at ThreadFunction");* *// //std::cout << "hello World " << std::endl;* *// //getchar();* *//}* *int main() * *{ * * using namespace boost::log::trivial; //for logging* * boost::log::sources::severity_logger_mt< boost::log::trivial::severity_level > lg;* * //WriteToLog("at main");* * //return 1;* * SERVICE_TABLE_ENTRY ServiceTable[2];* * ServiceTable[0].lpServiceName = "MemoryStatus";* * ServiceTable[0].lpServiceProc = (LPSERVICE_MAIN_FUNCTION)ServiceMain;* * ServiceTable[1].lpServiceName = NULL;* * ServiceTable[1].lpServiceProc = NULL;* * // Start the control dispatcher thread for our service* * StartServiceCtrlDispatcher(ServiceTable); * * return 0;* *}* *void ServiceMain(int argc, char** argv) * *{ * * int error; * * ServiceStatus.dwServiceType = SERVICE_WIN32; * * ServiceStatus.dwCurrentState = SERVICE_START_PENDING; * * ServiceStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwServiceSpecificExitCode = 0; * * ServiceStatus.dwCheckPoint = 0; * * ServiceStatus.dwWaitHint = 0; * * hStatus = RegisterServiceCtrlHandler(* * "MemoryStatus", * * (LPHANDLER_FUNCTION)ControlHandler); * * if (hStatus == (SERVICE_STATUS_HANDLE)0) * * { * * // Registering Control Handler failed* * return; * * } * * // Initialize Service * * //error = InitService(); * * error = 0;* * if (error) * * {* * // Initialization failed* * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * ServiceStatus.dwWin32ExitCode = -1; * * SetServiceStatus(hStatus, &ServiceStatus); * * return; * * } * * // We report the running status to SCM. * * ServiceStatus.dwCurrentState = SERVICE_RUNNING; * * SetServiceStatus (hStatus, &ServiceStatus);* * MEMORYSTATUS memory;* * // The worker loop of a service* * //boost::thread t(&ThreadFunction);* * while (ServiceStatus.dwCurrentState == SERVICE_RUNNING)* * {* * char buffer[16];* * GlobalMemoryStatus(&memory);* * sprintf(buffer, "%d", memory.dwAvailPhys);* * int result = WriteToLog(buffer);* * if (result)* * {* * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * ServiceStatus.dwWin32ExitCode = -1; * * SetServiceStatus(hStatus, &ServiceStatus);* * return;* * }* * Sleep(SLEEP_TIME);* * }* * return; * *}* *// Service initialization* *int InitService() * *{ * * int result;* * result = WriteToLog("Monitoring started.");* * return(result); * *} * *// Control handler function* *void ControlHandler(DWORD request) * *{ * * switch(request) * * { * * case SERVICE_CONTROL_STOP: * * WriteToLog("Monitoring stopped.");* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * SetServiceStatus (hStatus, &ServiceStatus);* * return; * * case SERVICE_CONTROL_SHUTDOWN: * * WriteToLog("Monitoring stopped.");* * ServiceStatus.dwWin32ExitCode = 0; * * ServiceStatus.dwCurrentState = SERVICE_STOPPED; * * SetServiceStatus (hStatus, &ServiceStatus);* * return; * * default:* * break;* * } * * // Report current status* * SetServiceStatus (hStatus, &ServiceStatus);* * return; * *} * *2. Dump* *Dump Summary* *------------* *Dump File: with_ssl_56.exe.4208.dmp : C:\Dumps\with_ssl_56.exe.4208.dmp* *Last Write Time: 9/26/2014 11:59:38 AM* *Process Name: with_ssl_56.exe : C:\lpa_c\wix_for_service\build_win\src\with_ssl_56\Debug\with_ssl_56.exe* *Process Architecture: x86* *Exception Code: 0xC0000005* *Exception Information: The thread tried to read from or write to a virtual address for which it does not have the appropriate access.* *Heap Information: Not Present* *System Information* *------------------* *OS Version: 6.0.6002* *CLR Version(s): * *Modules* *-------* *Module Name Module Path Module Version* *----------- ----------- --------------* *with_ssl_56.exe C:\lpa_c\wix_for_service\build_win\src\with_ssl_56\Debug\with_ssl_56.exe 0.0.0.0* *ntdll.dll C:\Windows\System32\ntdll.dll 6.0.6002.18881* *kernel32.dll C:\Windows\System32\kernel32.dll 6.0.6002.19034* *advapi32.dll C:\Windows\System32\advapi32.dll 6.0.6002.18005* *rpcrt4.dll C:\Windows\System32\rpcrt4.dll 6.0.6002.18882* *boost_log-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_log-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_date_time-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_date_time-vc100-mt-gd-1_56.dll 0.0.0.0* *MSVCP100D.dll C:\Windows\System32\MSVCP100D.dll 10.0.30319.1* *MSVCR100D.dll C:\Windows\System32\MSVCR100D.dll 10.0.30319.1* *boost_system-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_system-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_filesystem-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_filesystem-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_chrono-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_chrono-vc100-mt-gd-1_56.dll 0.0.0.0* *boost_thread-vc100-mt-gd-1_56.dll C:\boost_1_56_0_dyn\stage\lib\boost_thread-vc100-mt-gd-1_56.dll 0.0.0.0* *psapi.dll C:\Windows\System32\psapi.dll 6.0.6000.16386* *ws2_32.dll C:\Windows\System32\ws2_32.dll 6.0.6001.18000* *msvcrt.dll C:\Windows\System32\msvcrt.dll 7.0.6002.18551* *nsi.dll C:\Windows\System32\nsi.dll 6.0.6001.18000* *user32.dll C:\Windows\System32\user32.dll 6.0.6002.18005* *gdi32.dll C:\Windows\System32\gdi32.dll 6.0.6002.19171* *3. Call Stack* * 00000000() * * user32.dll!76659ce4() * * [Frames below may be incorrect and/or missing, no symbols loaded for user32.dll] * * advapi32.dll!77b84158() * * advapi32.dll!77b840f6() * * advapi32.dll!77b8430d() * * ws2_32.dll!7670ab6d() * * ws2_32.dll!7670aa95() * * ws2_32.dll!7670a3b2() * * ws2_32.dll!7670ae3f() * * ws2_32.dll!7670ad7a() * * ws2_32.dll!7670acc3() * * ws2_32.dll!7670ac2b() * * boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::winsock_init_base::startup(boost::asio::detail::winsock_init_base::data & d, unsigned char major, unsigned char minor) Line 39 + 0x2d bytes C++* * boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::winsock_init<2,0>::winsock_init<2,0>(bool allow_throw) Line 57 + 0xe bytes C++* *> boost_log-vc100-mt-gd-1_56.dll!boost::asio::detail::`dynamic initializer for 'winsock_init_instance''() Line 116 + 0x1c bytes C++* * MSVCR100D.dll!_initterm(void (void)* * pfbegin, void (void)* * pfend) Line 873 C* * boost_log-vc100-mt-gd-1_56.dll!_CRT_INIT(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 284 + 0xf bytes C* * boost_log-vc100-mt-gd-1_56.dll!__DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 506 + 0x11 bytes C* * boost_log-vc100-mt-gd-1_56.dll!_DllMainCRTStartup(void * hDllHandle, unsigned long dwReason, void * lpreserved) Line 476 + 0x11 bytes C* * ntdll.dll!77a112f4() * * ntdll.dll!779f906b() * * ntdll.dll!77a016d2() * * ntdll.dll!779fbf5a() *

2 1

[thread] Specific old move semantics usage
by Vicente J. Botet Escriba 27 Sep '14

27 Sep '14

Hi all, I would like to remove the specific move semantics included in Boost.Thread as it was flawed. This has been replaced by the Boost.Move one long time ago. Is there someone still using it? Could I at least define by the default (even for BOOST_THREAD_VERSION 2) BOOST_THREAD_USES_MOVE for Boost 1.57? Best, Vicente

1 0

Using boost::xpressing on Windows Store
by Paula Stanciu 27 Sep '14

27 Sep '14

Hello, I'm trying to use boost::xpressive on Windows Store and I ran into the following problem: Because _WIN32 is defined BOOST_XPRESSIVE_HAS_MS_STACK_GUARD gets defined and that causes the use of _resetstkoflw() that is not defined for windows sore ( http://msdn.microsoft.com/library/windows/apps/jj606124.aspx ) and so I cannot compile the code that uses boost::xpressive. I think BOOST_XPRESSIVE_HAS_MS_STACK_GUARD should not be defined for Windows store since it does not support _resetstkoflw() ? Any idea how I can solve this issue? Would it be the right thing to undefine this for Windows Store ? Thanks, Paula

3 2

Re: [Boost-users] Using boost::xpressive on Windows Store
by Paula Stanciu 27 Sep '14

27 Sep '14

Thanks Eric. Yes, it's if the WINAPI_FAMILY is set to WINAPI_PARTION_APP. Should I submit a patch with the changes I think should be done in this case ? It's actually just adding and extra check in xpressive_fwd.hpp before BOOST_XPRESSIVE_HAS_MS_STACK_ GUARD is defined. ( e.g. (WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP)) ) Best regards, Paula On Fri, Sep 26, 2014 at 6:19 PM, Eric Niebler <eniebler(a)boost.org> wrote: > On 9/26/2014 8:03 AM, Paula Stanciu wrote: > > Hello, > > > > I'm trying to use boost::xpressive on Windows Store and I ran into the > > following problem: > > > > Because _WIN32 is defined BOOST_XPRESSIVE_HAS_MS_STACK_GUARD gets > > defined and that causes the use of _resetstkoflw() that is not defined > > for windows sore ( > > http://msdn.microsoft.com/library/windows/apps/jj606124.aspx ) and so I > > cannot compile the code that uses boost::xpressive. > > > > I think BOOST_XPRESSIVE_HAS_MS_STACK_GUARD should not be defined for > > Windows store since it does not support _resetstkoflw() ? Any idea how I > > can solve this issue? Would it be the right thing to undefine this for > > Windows Store ? > > Sure. Is there some #define a program can check to see if it's being > compiled for Windows Store? > > Eric > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

1 0

BOOST_PP_ERROR(0x0003, BOOST_PP_REPEAT_OVERFLOW) with multiply nested BOOST_PP_REPEATS
by Colin Fowler 26 Sep '14

26 Sep '14

I'm having a problem with multiple nested repeats. I need to generate int x_0_0_0_0 to int x_a_b_c_d. Attempting to do so results in a BOOST_PP_ERROR. For readability, a few shorter defines #define TUPLE_ELEM BOOST_PP_TUPLE_ELEM #define REPEAT BOOST_PP_REPEAT and I also neglect the necessary BOOST_PP_CAT statements in DECL4D in this example #define DECL4D(z, n, text) TUPLE_ELEM(3, text) TUPLE_ELEM(0, text) TUPLE_ELEM(1, text) TUPLE_ELEM(2, text) n; #define DECL4C(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4D, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define DECL4B(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4C, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define DECL4A(z, n, text) REPEAT(TUPLE_ELEM(0, text), DECL4B, (TUPLE_ELEM(1, text), TUPLE_ELEM(2, text), n, TUPLE_ELEM(3, text))) #define decl4(a, b, c, d, text) REPEAT(a, DECL4A, (b, c, d, text)) decl4(1, 1, 1, 1, int x_) Am I hitting a nesting depth limit or something else? Is there a way around this? Ideally I want to write a decl5 macro and have successfully written a decl1, decl2 and decl3 so far Regards, Colin

2 3

[fusion] problem converting the result of a transform of a set into a map
by Christian Kerl 26 Sep '14

26 Sep '14

Hello everybody, I've a problem with the boost fusion library. I try to convert a fusion set into a map using the transform algorithm. Here is a example: typedef typename boost::fusion::result_of::as_map< typename boost::fusion::result_of::transform<BoundMembers, map_name_to_member>::type >::type Content; where BoundMembers is a boost::fusion::set and map_name_to_member is defined as: struct map_name_to_member { template <typename T> struct result; template <class F, typename T> struct result<F(T)> { typedef boost::fusion::pair<typename T::Name, typename T::Member> type; }; }; With boost 1.56 and gcc 4.8.1 I get the following compilation error: include/boost/fusion/iterator/key_of.hpp:36:16: error: invalid use of incomplete type ‘struct boost::fusion::extension::key_of_impl<boost::fusion::transform_view_iterator_tag>’ struct key_of ^ include/boost/fusion/iterator/key_of.hpp:21:16: error: declaration of ‘struct boost::fusion::extension::key_of_impl<boost::fusion::transform_view_iterator_tag>’ struct key_of_impl; However, this code used to work with Boost 1.48. I found a workaround to fix this, by converting the result of transform to a fusion list before coverting it to a map, i.e.: typedef typename boost::fusion::result_of::as_map< typename boost::fusion::result_of::as_list< typename boost::fusion::result_of::transform<BoundMembers, internal::map_name_to_member>::type >::type >::type Content; Am I doing something wrong or is this intended behavior? Thanks for your support. Best regards, Christian Kerl

1 0

Re: [Boost-users] boost logger architecture
by Savva Kuznetsov 26 Sep '14

26 Sep '14

Hi, Tony. It would be great to have an opportunity to know which file is currently being used for logging and set another, for example. Also, we want to control logs rotation and set conditions in which current file must be stored into collection, and create new file with the same name. It would be much easier task and I guess it would be the true boost-style, if boost\log\sinks\text_file_backend.cpp was not hiding a lot of definitions and class interfaces. S.K.

1 0

boost logger architecture.
by Savva Kuznetsov 25 Sep '14

25 Sep '14

Hello, guys. This post is almost the entire duplicate of my Ticket #10524. We're using boost logger in our application and it's really great boost library part. But, we need to change some of it's functionality. Actually, we need to add some lines of code in a method of collector class (for example, file_collector from boost\log\sinks\text_file_backend.cpp) I guess the right way to do this is inheritance from file_collector class and redefinition of it's members functions. But, since it's entire declaration and definition are in text_file_backend.cpp file in an anonymous namespace, it's impossible. Also, it would be cool to use some functions that this class uses (these functions are in text_file_backend.cpp file too for some unknown reason). The only solution I see is to copy-and-paste the entire file_collector class code from boost\log\sinks\text_file_backend.cpp and rewrite some of it's methods content, but, it's obviously wrong and not beautiful way (not boost-way). I guess boost must provide an extensible way to do things. Is there any reason that the entire class is in text_file_backend.cpp file or maybe I am missing something? My ticket have been closed by the author of logger with the comment: "file_collector in text_file_backend.cpp is not designed to be extensible because the interface for the extension is not clear. This made the implementation simpler." It's kinda strange reason, is it?

3 2

List of supported locales and time-zones
by niXman 25 Sep '14

25 Sep '14

Hi, Can somebody tell me please, how can I get a list of supported locale names and time-zones using boost.locale? Thanks. -- Regards, niXman ___________________________________________________ Dual-target(32 & 64-bit) MinGW-W64 compilers for 32 and 64-bit Windows: http://sourceforge.net/projects/mingw-w64/ ___________________________________________________ Another online IDE: http://liveworkspace.org/

1 0

boost.python built with VC2010
by Mohammed El-Afifi 25 Sep '14

25 Sep '14

Hello, I have successfully built boost.python with visual c++ 2010(dynamic library, 64-bit). I have python 2.7.8 64-bit installed on windows 7 64-bit. I've read here https://docs.python.org/2/distutils/apiref.html#module-distutils.msvccompil… that python extensions should be built with the same compiler that was used to build python itself. My question is, since python 2.7.8 was built with visual c++ 2008 64-bit compiler, can I have the following mix a) my python extension built with VC2008 64-bit(to match python itself) b) 64-bit boost.python dll built with VC2010 64-bit c) python 64-bit, built itself with VC2008 64-bit? I've noticed that boost.python dll depends on python dll and that's why I'm quite worried about the mix. Appreciating your insights.

1 0

[boost/config] BOOST_LIKELY argument requirements
by Stephan Bergmann 25 Sep '14

25 Sep '14

Looking at the definition of BOOST_LIKELY as #define BOOST_LIKELY(x) __builtin_expect(x, 1) in boost/config/compiler/{clang,intel,gcc}.hpp, and given that at lest the GCC and Clang __builtin_expect has a first parameter of type long, I wonder (1) whether it would be better to define it as #define BOOST_LIKELY(x) __builtin_expect(bool(x), 1) so that > $ cat test.cc > #include "boost/config.hpp" > #include "boost/logic/tribool.hpp" > int f(boost::tribool b1, boost::tribool b2) { > if (b1) return 1; > else if (BOOST_LIKELY(b2)) return 2; > else return 3; > } > > $ g++ -c test.cc > In file included from .../boost_1_56_0/boost/config.hpp:39:0, > from test.cc:1: > test.cc: In function ‘int f(boost::logic::tribool, boost::logic::tribool)’: > .../boost_1_56_0/boost/config/compiler/gcc.hpp:90:46: error: cannot convert ‘boost::logic::tribool’ to ‘long int’ for argument ‘1’ to ‘long int __builtin_expect(long int, long int)’ > #define BOOST_LIKELY(x) __builtin_expect(x, 1) > ^ > test.cc:5:14: note: in expansion of macro ‘BOOST_LIKELY’ > else if (BOOST_LIKELY(b2)) return 2; > ^ would not fail (effectively changing the requirement for the argument to BOOST_LIKELY from "[the] expression should result in a boolean value" to "it should be contextually convertible to bool"). (2) if not that, whether to at least wrap the expansion of x in parentheses, #define BOOST_LIKELY(x) __builtin_expect((x), 1) Stephan

1 0

[assign][ptr_container] Exception safety of ptr_list_of, ptr_push_back, ptr_map_insert, etc.
by Aaron Levy 25 Sep '14

25 Sep '14

I am trying to understand how ptr_list_of or ptr_push_back provide more exception safety. I can write something like: boost::ptr_vector<Foo> vec; push_back(vec)(new Foo)(new Foo); Is the order of evaluation of the two "new Foo" expressions indeterminate here? If not, then if the second new throws, the destructor of vec should be invoked. The Foo object allocated by the first new and now part of vec should also get released as part of that. -- Aaron Levy aaron.levy(a)yandex.com

3 3

[Log] reversed file rotation order...
by Ovanes Markarian 24 Sep '14

24 Sep '14

Hi *, We use file rotation with boost log, since I work more and with Python I use Python's logging as well. One interesting feature I observed was that Python's logger does reversed file rotation. Is that sort of feature implemented with boost::log library? In boost the rotation is: whatever_0.log < oldest file whatever_1.log whatever_2.log < newest file In Python the rotation order is: whatever_0.log < newest file whatever_1.log whatever_2.log < oldest file I think this is a very cool how Python does it, since I am able to endlessly "tail" in the shell the log file: tail -f whatever_0.log will not stop until I cancel the tail operation. With boot it is like, logger writes a new file and tail hangs with the file which is no longer written. This is a bit unusable and confusing. Would be great if that'd be possible in boost. Thanks, Ovanes

1 0

Problems Linking with Boost Serialization
by Isaac Lascasas 24 Sep '14

24 Sep '14

I have found this on boost 1.56 with msvc12: Error 119 error LNK2005: "bool __cdecl boost::archive::detail::is_whitespace<char>(char)" (??$is_whitespace@D @detail@archive@boost@@YA_ND@Z) already defined in libboost_wserialization-vc120-mt-1_56.lib(basic_text_wiprimitive.obj) C:\supernova\sb6\src\supernova_clr\libboost_serialization-vc120-mt-1_56.lib(basic_text_iprimitive.obj) Error 120 error LNK2005: "bool __cdecl boost::archive::detail::is_whitespace<wchar_t>(wchar_t)" (??$is_whitespace@ _W@detail@archive@boost@@YA_N_W@Z) already defined in libboost_wserialization-vc120-mt-1_56.lib(basic_text_wiprimitive.obj) C:\supernova\sb6\src\supernova_clr\libboost_serialization-vc120-mt-1_56.lib(basic_text_iprimitive.obj) This code used to link fine with previous boost versions. Now it looks like you can't use both archive and warchive at the same time. I'm using xml warchives for serializing in my code. Regards. Isaac Lascasas.

2 2

Boost::Locale jam file seems to be outdated for ICU ver. 53.1
by Caroline Beltran 24 Sep '14

24 Sep '14

I'm using Boost::Locale (and ICU) for the first time but I strongly believe that the jam file is referencing old ICU dll filenames. Current ICU dlls: icuucd53.dll icudt53.dll icuind53.dll icuin53.dll Relevant snippet from jam file (Boost 1.56): searched-lib icuuc : : <toolset>msvc <variant>debug <name>icuucd <search>$(ICU_PATH)/lib <link>shared <runtime-link>shared ; To me it appears that the snippet above is referring to icuucd when it should be referring to icuucd53. I've been trying really hard to get Boost::Locale going on my system. I updated all references to dlls and this is the result of the config test. As you can see, I am not linking with ICU (even though ICU was installed correctly and ICU test results were successful). I think that the jam file may need further changes. Please advise. D:\boost_1_56_0\stage\lib>test_config - Backends: std winapi - Without iconv - Environment LANG= LC_ALL= LC_CTYPE= TZ= - C locale: English_United States.1252 - C++ locale: English_United States.1252 - Testing locales availability on the operation system: locale C C++ en_US.UTF-8 No No en_US.ISO8859-1 No No English_United States.1252 Yes Yes he_IL.UTF-8 No No he_IL.ISO8859-8 No No Hebrew_Israel.1255 Yes Yes ru_RU.UTF-8 No No Russian_Russia.1251 Yes Yes tr_TR.UTF-8 No No Turkish_Turkey.1254 Yes Yes ja_JP.UTF-8 No No ja_JP.SJIS No No Japanese_Japan.932 Yes Yes - Testing timezone and time Local Time :%c=09/23/14 15:18:07; %Z=Central Daylight Time (Mexico); %z=Central Daylight Time (Mexico) Universal Time:%c=09/23/14 20:18:07; %Z=Central Standard Time (Mexico); %z=Central Standard Time (Mexico) - Boost.Locale's locale: en_US.UTF-8

2 1

Adding more than 20 rows in transition table for Boost::MSM
by Yechiel Levi 23 Sep '14

23 Sep '14

Hi, I tried defining: #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_VECTOR_SIZE 30 // or whatever you need #define BOOST_MPL_LIMIT_MAP_SIZE 30 // or whatever you need /// Boost-MSM Includes // back-end #include "boost/mpl/vector/vector30.hpp" #include <boost/msm/back/state_machine.hpp> //front-end #include <boost/msm/front/state_machine_def.hpp> #include <boost/msm/front/functor_row.hpp> #include <boost/any.hpp> // for And_ operator #include <boost/msm/front/euml/operator.hpp> And i still get the following errors: builder1: In file included from /usr/local/include/boost/mpl/erase.hpp:19, builder1: from /usr/local/include/boost/fusion/mpl/erase.hpp:10, builder1: from /usr/local/include/boost/fusion/mpl.hpp:20, builder1: from /usr/local/include/boost/fusion/include/mpl.hpp:11, builder1: from /usr/local/include/boost/msm/back/state_machine.hpp:30, builder1: from File_Meta_FSM.h:18, builder1: from Open_Files_Mng.h:5, builder1: from Open_Files_Mng.cpp:1: builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: template argument 1 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:56: error: template argument 2 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:57: error: template argument 3 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: ‘_’ was not declared in this scope builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: template argument 1 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:62: error: template argument 2 is invalid builder1: /usr/local/include/boost/mpl/aux_/erase_impl.hpp:63: error: template argument 3 is invalid and more of the same errors.. -- Kind regards, Yechiel Levi

5 7

Graph concepts for Dijkstra shortest-path searches
by Clayton Davis 22 Sep '14

22 Sep '14

Hi, I am somewhat uncertain on which concepts are required for the Dijkstra searches in the BGL and parallel BGL. For the sequential BGL, documentation at http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/dijkstra_shortest_paths… would seem to indicate that a VertexListGraph is required, even when the no_init version is used. Looking at the code, I think that is accurate - use of the index map at https://github.com/boostorg/graph/blob/master/include/boost/graph/dijkstra_… seems to require vertex list traversal - but I would also think that defeats the purpose of the no_init option. Conversely, for the parallel BGL documentation at http://www.boost.org/doc/libs/1_56_0/libs/graph_parallel/doc/html/dijkstra_… says only that DistributedGraph is required, which is a refinement of Graph but not VertexListGraph or IncidenceGraph. However, just a little bit of searching seems to show that the parallel Dijkstra search requires both, along with perhaps PropertyGraph (see for instance https://github.com/boostorg/graph_parallel/blob/master/include/boost/graph/… and https://github.com/boostorg/graph_parallel/blob/master/include/boost/graph/…) I won't pretend to understand the code; but I would expect these functions to require something stronger than the documentation indicates. Could someone please clarify what the requirements are for these functions? Any help is greatly appreciated. Thanks, Clayton

1 0

BOOT_PP_REPEAT simple nesting problem
by Colin Fowler 22 Sep '14

22 Sep '14

Hi all, I'm trying to use BOOST_PP to generate some code. I can generate the sequence int x_0 to int x_4 using the code below. #include <boost/preprocessor/repetition/repeat.hpp> #define DECL1(z, n, text) text ## _ ## n = n; #define decl1(text, count) BOOST_PP_REPEAT(count, DECL1, text) decl1 (int x, 5) What I'd like to do is write a decl2 that can be used something like this: decl2 (int x, 5, 2) to generate int x_0_0 to int x_4_1 I've tried nesting BOOST_PP_REPEAT but so far I've been unable to produce the desired behaviour unless I hardcode one of the iteration counts. I'd like to also eventually write a decl3(int x, 5, 3, 4) when I understand how a decl2 would work. Any help much appreciated! Regards, Colin

4 6

[assign][cref_list_of] Creating anonymous list of pairs
by Aaron Levy 22 Sep '14

22 Sep '14

Is there a way to generate a list of value pairs using ref_list_of or cref_list_of. Maybe such a list could be assigned to a map. Something like: ref_list_of<size, std::pair<std::string, std::string>>("foo", "bar")("foo1", "bar1")...; or std::map<string, string> names = ref_list_of<size, std::pair<std::string, std::string>>("foo", "bar")("foo1", "bar1")...; -- Aaron Levy aaron.levy(a)yandex.com

3 2

[ptr_container][ptr_map]
by Aaron Levy 22 Sep '14

22 Sep '14

Consider the following code: class Base { public: virtual ~Base() = 0 {}; virtual double get() = 0; }; class D1 : public Base { public: D1(double n) : val_(n) {} double get() const { return val_; } private: double val_; }; class D2 : public Base { D2(double n) : val_(n) {} double get() const { return val_; } private: double val_; }; bool operator < (const Base& left, const Base& right) { return (left.get() < right.get()); } I can create a ptr_set of Base like this: boost::ptr_set<Base> set; But I can't create a ptr_map with Base as key, like this: boost::ptr_map<Base, Base> map; The problem is that Base is abstract and so the key cannot be instantiated by ptr_map. What is the cause for this distinction between ptr_set and ptr_map. -- Aaron Levy aaron.levy(a)yandex.com

2 1

Boost.Test multiple linkage question
by Rob Harris 22 Sep '14

22 Sep '14

All, I've been ripping out my hair all day, and I can't seem to determine a straight answer from the Googles. Can I link _multiple_ boost unit test dynamic libraries into a single binary and have all of them detected? For instance... src lib liba foo.cpp liba_unittests.cpp libb bar.cpp libb_unittests.cpp libd baz.cpp libd_unittests.cpp lib liba.so liba_ut.so libb.so libb_ut.so libd.so libd_ut.so bin ut unittest_driver When I build this infrastructure out, everything compiles. I've checked the compilation command and it looks like everything is on the command line, but there's explicit indication that unittest_driver actually read or linked any of the lib*_ut.so files. If I make individual unit test drivers in, say, liba, the driver works fine. If I link everything into a single unittest_driver binary, I keep getting the dreaded empty test tree. I have -DBOOST_ALL_DYN_LINK set in my CXXFLAGS so that shouldn't be the problem. And I only have BOOST_TEST_MAIN set in the driver; still no joy. Any help (or a definitive, "no you idiot, you can't do that!") would be greatly appreciated. Thanks. -RMH

2 1

Utah C++ User Group started
by legalize+jeeves＠mail.xmission.com 22 Sep '14

22 Sep '14

[Please do not mail me a copy of your followup] I'm booting up a C++ User Group in Utah. We're bootstrapping out first meeting to decide a regular meeting time and location. Join the Utah C++ Programmers MeetUp group to hear about meetings: <http://www.meetup.com/Utah-Cpp-Programmers/> Follow related evens on the Utah C++ Users Group blog: <http://utahcpp.wordpress.com> -- "The Direct3D Graphics Pipeline" free book <http://tinyurl.com/d3d-pipeline> The Computer Graphics Museum <http://computergraphicsmuseum.org> The Terminals Wiki <http://terminals.classiccmp.org> Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>

1 0

[lockfree] stack needs undocumented trivial assignment
by Norbert Wenzel 21 Sep '14

21 Sep '14

I'm trying to replace some computation intensive loops in legacy code with parallel loops and thus tried to store the results in a lockfree stack. I've chosen stack over queue because of the requirements stated in the documentation, where stack only needs a copy ctor and queue additionally needs trivial assignment and trivial dtor. My result struct I want to store in the stack is *not* trivially assignable. When trying to compile the code containing my lockfree::stack the static assertion in line 75 of stack.hpp because it requires trivial assignment and trivial dtor. My question would be if this is simply an error in the documentation ie. if the requirements section should be copied over from lockfree::queue or if these static assertions should only be checked in some special case, eg. where the stack is of fixed size? thanks, Norbert

1 0

[context] How to set stack pointer in a platform-independent way?
by TONGARI J 21 Sep '14

21 Sep '14

Hi, The problem had been discussed here: https://groups.google.com/forum/#!topic/boost-devel-archive/cl8B1oUPrVM But it's still not clear how to set the stack pointer portably, even after examining the code of Boost.Coroutine. For now, Boost.Context only supports downward stack, and Boost.Coroutine, which happened to be written by the same author, just assumes that the stack always grows downward, which is not really a portable implementation, if future Boost.Context supports upward stack, Boost.Coroutine has to be changed as well. Even than that, what does "beginning of the stack" really means? Suppose we have a stack of size 3, starting at [s]: [s-1][s][s+1][s+2][s+3] Why the beginning of a downward stack is [s+3], not [s+2]? If it's a upward stack, is beginning [s] or [s-1]? Thanks.

5 12

from: giridhar
by giridhar 20 Sep '14

20 Sep '14

Salutations boost http://ariasking.com/morning.php/ttqhx3144vcfnpry/ giridhar

1 0

[ASIO] [SSL] [SOCKS4] Layers
by Maciej Miszczak 19 Sep '14

19 Sep '14

Hello, I have been successfully using ASIO for a long time, but recently I try to use SSL over SOCKS 4 and I'm struggling with short read while asynchronous SSL handshaking. I have come across this: http://stackoverflow.com/questions/9943541/boost-asio-how-to-read-write-on-…] but it's only partially helpful. I haven't find any good explanation, what the layers really are (ex. I can't assign next_layer and lowest_layer to any of OSI layers). Could someone explain the meaning of next_layer and lowest_layer and how to use SSL stream with SOCKS 4 proxy. Best regards, Maciej Miszczak

2 2

Re: [Boost-users] Boost XML Serialization
by Manasi Deshpande 19 Sep '14

19 Sep '14

Hello All, Currently I am working on DB Driven C++ API, where it also involves XML processing functionalities. That's where I came across Boost Serialization. We have a very peculiar story here, and it goes like this: We have 2 identical APIs. One in C# and another in C++. Both are DB driven similar APIs. There are instances, where any XML data serialized on C++ platform needs to be de serialized on C# and vice versa. In C# life is straight forward; one needs no bothering about serialization and de serialization. I think in boost you can de serialize the XML document only if it is built using Boost Serialization. I think it is the case in C# also. Is there any way out, where Boost Serialization can be customized? Please forgive me if I am not clear in stating my problem statement! -------------------------------------------------------------------------------------------------- This email and any attachments are confidential and are for the use of the addressee only. If you are not the addressee, you must not use or disclose the contents to any other person. Please immediately notify the sender and delete the email. Statements and opinions expressed here may not represent those of the company. Email correspondence is monitored by the company. This information may be subject to export control regulation. You are obliged to comply with such regulations. Renishaw plc (company number 1106260) and Wotton Travel Limited (company number 01973158) are companies registered in England and Wales with a registered office at New Mills, Wotton-under-Edge, Gloucestershire, GL12 8JR, United Kingdom, Telephone +44 1453 524524. --------------------------------------------------------------------------------------------------

2 1

[logging+unittest]
by Witold E Wolski 19 Sep '14

19 Sep '14

Hi, I need to integrate some loggin into my unit to some extend bein integration tests (hardware). How best to call this function which sets up boost logging void init() { boost::log::add_file_log("sample.log"); boost::log::core::get()->set_filter ( boost::log::trivial::severity >= boost::log::trivial::info ); } if I have a test Runner looking like: #define BOOST_TEST_MODULE MasterTestSuite #include <boost/test/unit_test.hpp> Is there a way not have to add the suites manually Thanks. -- Witold Eryk Wolski

1 1

[thread] memory synchronization multiple mutexes
by firespot 19 Sep '14

19 Sep '14

Hi, How does memory synchronization and visibility behave when multiple mutexes are involved? I have two groups of threads (boost::thread_group) and two mutexes (boost::mutex m1, boost::mutex m2) + associated condition variables, with each thread group being responsible to write to some variables (here Ptr, run) and consistently using "its" mutex for locking. However there is a piece of code that looks - much simplified - like this: void f() { { boost::unique_lock<boost::mutex> Lock(m1); Ptr = someAddress; // set the Ptr from 0 to some memory address } { boost::unique_lock<boost::mutex> Lock(m2); run = 1; // was 0, inform that execution can proceed condVar2.notify_all(); } ... // wait until Ptr has been reset to 0 { boost::unique_lock<boost::mutex> Lock(m1); while (Ptr != 0) condVar1.wait(Lock); } } and another function: void g() { { boost::unique_lock<boost::mutex> Lock(m2); while (run == 0) condVar2.wait(Lock); } // run the execution, e.g. std::copy(Ptr, Ptr + 100, Target); // finally all finished, signal back that Ptr is not needed any more { boost::unique_lock<boost::mutex> Lock(m1); Ptr = 0; condVar1.notify_all(); } } f() is only invoked from a thread of the first group, and g() only from a thread of the second group. Whenever Ptr might get changes the first mutex (m1) and its associated condition-variable is used, and whenver run might get changed the second mutex and its associated conditional variable is used. The control flow guarantees that run is not set to 1 prior to Ptr being set, and thus in g() the "running" itself (here the std::copy) cannot commence earlier. However, what puzzles me now: I used a different mutex for setting Ptr and setting/checking run. Does this have any impact whatsoever on memory visibility across the threads in the two thread-groups? Specifically, is it always guaranteed that when g() continues its execution (because run == 1) that it must see the correct value of Ptr (a non-NULL value)? Or is it possible that it still sees 0 and I'd have to make a separate locking involving m1 to guarantee a proper read for Ptr as anything written under a lock of m1 is also only guaranteed to be later properly read if the locking also used m1? thanks!

2 1

[mpl] simple mpl::transform with placeholder?
by Andrew King 19 Sep '14

19 Sep '14

Hi, Lets say I have an mpl vector defined as : template <typename Traits> struct A { }; template <typename Traits> struct B { }; typedef mpl::vector<A<mpl::_>, B<mpl::_> > MyVec; struct MyTraits {}; How do I 'apply' or transform MyVec with MyTraits? ie. I want the mpl::vector ... boost::mpl::vector<A<MyTraits>, B<MyTraits>>; I realise I can do mpl::apply<A<mpl::_>, MyTraits> to get A<MyTraits> but I can't work out how to do the equivalent to the entire vector. mpl::transform seems like what I should be using. Transform seems to do apply internally, but I can't work out the syntax to do something like: using substituted = typename boost::mpl::transform<MyVec, boost::mpl::apply<boost::mpl<_>, MyTraits> >::type; (This isn't right!) It may be I am confused because inside the transform, boost::mpl::_1 is the item in the vector, not the 'inner' placeholder. Sorry if this is a basic question ... Regards, Andrew

1 0

[Thread] Read-write locks
by lfrfly＠icqmail.com 18 Sep '14

18 Sep '14

I'm trying to create a standard read/write lock using Boost Threads, and I'm having a bit of difficulty mapping the Boost concepts onto the usual ones. A read/write lock should have several states: Locked for reading (multiple threads may lock at once), locked for writing (only one thread may lock, and no threads may be locked for reading at the same time), and unlocked. Ideally it would be nice if an RWL which is locked for reading may temporarily upgrade to locked for writing, then return to the locked for reading state. Boost supports several relevant notions of locking: shared locking, upgrade locking, and exclusive locking. This to me is a confusing distinction. In particular, a shared_mutex seems appropriate as the basis for a RWL, but is lock_upgrade() the equivalent of a write lock and lock_shared the equivalent of a read lock? This is unclear. If "upgrade locking" is not the same as "exclusive locking", then is an upgrade lock actually exclusive? Could someone please clarify this.

4 3

Numeric Cast from integer to floating point
by dariomt＠gmail.com 17 Sep '14

17 Sep '14

Hi, Quoting the docs for boost::numeric_cast: "There are several situations where conversions are unsafe: [...] Conversions from floating point types to integral types." What about conversions from integral types to floating point types? E.g. from 64bit int to double. The following example shows what I mean: #include <iostream> #include <cmath> #include <boost/numeric/conversion/cast.hpp> int main() { const uint64_t i = 123445678911188878; std::cout << "i=" << i << std::endl; const double d = i; std::cout << "d=" << std::fixed << d << std::endl; std::cout << "next=" << std::fixed << std::nextafter(d, std::numeric_limits<double>::max() ) << std::endl; std::cout << "prev=" << std::fixed << std::nextafter(d, -std::numeric_limits<double>::max()) << std::endl; // I'd expect the following cast to fail const double dd = boost::numeric_cast<double>(i); std::cout <<"dd=" << std::fixed << dd << std::endl; return 0; } prints i=123445678911188878 d=123445678911188880.000000 next=123445678911188896.000000 prev=123445678911188864.000000 dd=123445678911188880.000000 because that integer cannot be represented in double precision Is there something in Boost to help here? Thanks in advance

5 4

value_type in Typed In Place Factory
by Adam Badura 17 Sep '14

17 Sep '14

According to header file boost/utility/typed_in_place_factory.hpp (as linked from documentation: http://www.boost.org/doc/libs/1_55_0/boost/utility/typed_in_place_factory.h…) typed_in_place_factory has member type value_type which is the constructed type. Yet documentation ( http://www.boost.org/doc/libs/1_55_0/libs/utility/in_place_factories.html) fails to mention it. Why? Is it not part of the interface (I would assume so based on not mentioning it in documentation...)? Or was it just forgotten? I find such value_type quite useful... And since I'm already writing let me note that the mentioned documentation has also another minor issue. In Specification section the sample in_place_factory and typed_in_place_factory should be named in_place_factory1 and typed_in_place_factory1. As this is how they are really named. Or it should be stated explicitly that the actual name is implementation dependent. Adam Badura

1 0

Boostlog and ASIO crash in shared library
by Ray Cheng 17 Sep '14

17 Sep '14

Hi, My project use a simple main using dlopen to "run" the real main function in target shared library. I use both Boost Log and ASIO (for threadpool) in the project. In Linux I found the ASIO got weird behavior with some un-initialized variables and crashing all the time. I am able to trim down my problem into a small program as below: // *** threadpool.cpp *** #include <iostream> #include <memory> #include <boost/asio/io_service.hpp> #include <boost/bind.hpp> #include <boost/thread/thread.hpp> void print() { std::cout << "print" << std::endl; } struct ThreadPool { void start() { boost::asio::io_service ioService; boost::thread_group threadpool; std::unique_ptr<boost::asio::io_service::work> work = std::make_unique<boost::asio::io_service::work>(ioService); threadpool.create_thread(boost::bind(&boost::asio::io_service::run, &ioService)); for (int i=0; i<100; ++i) { ioService.post(&print); } std::cout << "Post all calculation tasks" << std::endl; work.reset(); threadpool.join_all(); ioService.stop(); std::cout << "Finished all calculation tasks" << std::endl; } }; extern "C" void createthreadpool() { ThreadPool pool; pool.start(); } // *** threadpool.cpp *** g++ -O0 -std=gnu++1y -fPIC -c -g -DLinux -DGNU_GCC -I${BOOST_HOME}/include threadpool.cpp g++ -shared -o libthreadpool.so threadpool.o -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -ldl -lstdc++ // *** main.cpp *** #include <dlfcn.h> #include <iostream> int main(int argc, char** argv) { typedef void* createProcess(); auto service = dlopen("libthreadpool.so", RTLD_LAZY); createProcess* make = reinterpret_cast<createProcess*>(dlsym(service, "createthreadpool")); std::cout << "dlsym" << std::endl; make(); return 0; } // *** main.cpp *** g++ -O0 -std=gnu++1y -fPIC -c -g -DLinux -DGNU_GCC main.cpp // Link against boost_log to simulate my problem (although it is not using any boost_log). This version will crash g++ -o main.bad main.o -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -lboost_log -ldl -lstdc++ // it works fine If link against libthreadpool, surprising me g++ -o main main.o -L/home/sysmmbuild/dev/boost -lthreadpool -L${BOOST_HOME}/lib -lboost_system -lboost_date_time -lboost_thread -lboost_filesystem -lboost_regex -lboost_chrono -lboost_log -ldl -lstdc++ One more finding is, if compile boost_log without thread support, the main.bad also working fine. I have attached the code and make.sh as make script. Software version Redhat enterprise 6.5 g++ 4.9.1 Boost 1.56.0 Rgds, Ray

2 2

[Thread] thousands of spurious wakeups from timed_wait() per second
by Steven Clark 15 Sep '14

15 Sep '14

I've been trying to get useful behavior out of condition_variable::timed_wait() with little success. Depending on the platform, I'm getting about 3000 or nearly 100000 spurious wakeups per second. I'm working on a few different Linux platforms with different versions of Boost: 1.46, 1.48, and another in the high 40's. The eventual target is 1.48. I've looked for bug reports and haven't found any, and I have no evidence yet that suggests the different versions are significant to this problem. Because of the lack of problem reports, I figure I'm doing something wrong. That's my question: "What am I doing wrong here?" I have a test program that sets up a typical producer/consumer example. The main program spawns a thread, the producer, that notifies the main thread via a condition_variable once a second for a few seconds, then ends. The main thread, the consumer, waits efficiently for notifications with a 2-second timeout. When the producer thread finishes, the main (consumer) thread eventually times out, joins the spawned thread, and exits. At least, that's what is supposed to happen. If I don't bother with timeouts and use condition_variable::wait(), it works perfectly - except for the timeout, join, and exit. This is as expected. So far I have seen no spurious wakeups at all with this test. There is an ominous yet ambiguous remark in the documentation "The duration overload of timed_wait is difficult to use correctly. The overload taking a predicate should be preferred in most cases." Due to that remark I stopped experimenting with relative timeouts before I got anything to work. Using absolute timeouts, I get very high numbers of spurious wakeups as mentioned above - 3000 and about 100000 per second depending on the platform. I see no difference between timed_wait with a predicate and without a predicate. I'm also having trouble with the return value of timed_wait(). The documentation carefully states that timed_wait() returns "false if the call is returning because the time specified by abs_time was reached, true otherwise". This seems to mean that spurious wakeups return true -- and if you think about it, the return value is useless if spurious wakeups could return false. You'd have to add your own check for timeout. I was quite surprised to find that every spurious wakeup of timed_wait() that I've ever seen returns false. That just doesn't make sense to me. Here is the version of my test program that uses timed_wait without a predicate, followed by its output. #include <boost/thread.hpp> #include <boost/date_time.hpp> #include <iostream> boost::condition_variable gCond; boost::mutex gMutex; bool gGotData; unsigned gValue; void threadfn() { for (unsigned i = 0; i < 7; i++) { std::cerr << "hello from threadfn(), #" << i << std::endl; { boost::lock_guard<boost::mutex> guard(gMutex); gGotData = true; gValue = i; } gCond.notify_one(); boost::this_thread::sleep(boost::posix_time::seconds(1)); } } int main() { std::cerr << "******* Using timed_wait()" << std::endl; gGotData = false; gValue = 999; boost::thread t(threadfn); while (true) { boost::system_time deadline( boost::posix_time::microsec_clock::local_time()); std::cerr << "now is " << deadline << std::endl; deadline += boost::posix_time::seconds(2); std::cerr << "deadline is " << deadline << std::endl; boost::unique_lock<boost::mutex> lock(gMutex); unsigned nWakeups = 0; while(!gGotData) { bool ret = gCond.timed_wait(lock, deadline); nWakeups++; if (ret) std::cerr << "timed_wait() returned true on wakeup #" << nWakeups << std::endl; } std::cerr << "main() exited inner loop with " << nWakeups << " wakeups; gGotData is " << (gGotData ? "true" : "false") << std::endl; if (gGotData) { std::cerr << "main(), notified, gValue is " << gValue << std::endl; gGotData = false; } } // not reached in this incarnation of the code t.join(); std::cerr << "main(), after joining" << std::endl; } ******* Using timed_wait() now is 2014-Sep-09 20:48:12.183781 deadline is 2014-Sep-09 20:48:14.183781 hello from threadfn(), #0 timed_wait() returned true on wakeup #1451 main() exited inner loop with 1451 wakeups; gGotData is true main(), notified, gValue is 0 now is 2014-Sep-09 20:48:12.215471 deadline is 2014-Sep-09 20:48:14.215471 hello from threadfn(), #1 timed_wait() returned true on wakeup #96864 main() exited inner loop with 96864 wakeups; gGotData is true main(), notified, gValue is 1 now is 2014-Sep-09 20:48:13.216511 deadline is 2014-Sep-09 20:48:15.216511 hello from threadfn(), #2 timed_wait() returned true on wakeup #95911 main() exited inner loop with 95911 wakeups; gGotData is true main(), notified, gValue is 2 now is 2014-Sep-09 20:48:14.216805 deadline is 2014-Sep-09 20:48:16.216805 hello from threadfn(), #3 timed_wait() returned true on wakeup #97526 main() exited inner loop with 97526 wakeups; gGotData is true main(), notified, gValue is 3 now is 2014-Sep-09 20:48:15.217191 deadline is 2014-Sep-09 20:48:17.217191 hello from threadfn(), #4 timed_wait() returned true on wakeup #104710 main() exited inner loop with 104710 wakeups; gGotData is true main(), notified, gValue is 4 now is 2014-Sep-09 20:48:16.217453 deadline is 2014-Sep-09 20:48:18.217453 hello from threadfn(), #5 timed_wait() returned true on wakeup #102404 main() exited inner loop with 102404 wakeups; gGotData is true main(), notified, gValue is 5 now is 2014-Sep-09 20:48:17.217685 deadline is 2014-Sep-09 20:48:19.217685 hello from threadfn(), #6 timed_wait() returned true on wakeup #97906 main() exited inner loop with 97906 wakeups; gGotData is true main(), notified, gValue is 6 now is 2014-Sep-09 20:48:18.217291 deadline is 2014-Sep-09 20:48:20.217291 ^C Thank you very much, Steven Clark

4 9

[fusion] BOOST_FUSION_DEFINE_STRUCT with user defined methods
by Tobias Loew 15 Sep '14

15 Sep '14

Hi, I often use BOOST_FUSION_DEFINE_STRUCT not to generate a fusion-sequence per se, but to get a struct with - default initialisation for all members - a reasonable set of constructors - equality-check - all above without additional code But sometimes I would like to have additional methods in those structs, but deriving from those or fusion-adapting them loses at least one of the nice properties above. After looking at the BOOST_FUSION_DEFINE_STRUCT implementation I though about splitting the makro BOOST_FUSION_DEFINE_STRUCT_IMPL an inject my code in-between. Now my questions are: - Is there anything I've overseen and might detroy some fusion-mechanism? - Is there any chance to get macros like BOOST_FUSION_DEFINE_STRUCT_[BEGIN|END] (and also for the other BOOST_FUSION_DEFINE_... macros? Tobias -- View this message in context: http://boost.2283326.n4.nabble.com/fusion-BOOST-FUSION-DEFINE-STRUCT-with-u… Sent from the Boost - Users mailing list archive at Nabble.com.

4 8

WG: [atomic] can it bechecked that boost::atomic<T> *v = reinterpret_cast<boost::atomic<T>*>(var); is safe?
by Tim Odenthal 15 Sep '14

15 Sep '14

On 15 Sep 2014, at 18:00, boost-users-request(a)lists.boost.org<mailto:boost-users-request@lists.boost.org> wrote: On Monday, September 15, 2014 07:31 PM, Tim Odenthal wrote: Dear experts, essentially, I use this type of reinterpret_cast for doubles, and it __seems__ to work fine. I compile-time check that the sizeof(boost::atomic<T>) == sizeof( T ), but is that enough to ensure that this will always work? Should/could I check alignment issues as well? Even if the "atomic_cast" function has a (small) run-time overhead, it would be very much worth it in my setting, where I actually want to safely add to a double at some location in memory. Obviously, I want to use boost::atomic to be system/compiler agnostic, since it's supposed to eventually run with clang, gcc, (linux, OS X) as well as MS compilers, and so far we didn't see the need to move to C++11... I'm not sure I can figure out what problem you're trying to solve. Well, essentially, I have an array of doubles that at exactly one point in the code needs to be added to where I cannot ensure that each thread only adds to its own part of the array, so I want to ensure that each addition there is executed atomically. I think the cast is probably "safe", but far less can be said of it when it's dereferenced. That would depend entirely on the type of var. Is *var actually a boost::atomic<T> in the first place? If it is, why are you erasing its type? No, as I was saying, it’s a double *. How can you be sure there is nobody else aliasing var or *var and then reading or writing it? That is actually a problem, but since I completely control that part of the code, I hope to not make that mistake ;-). If *var is not a boost::atomic<T>, reinterpret_cast isn't going to magically convert it, you have undefined behaviour. Of course, one effect of UB is that it __seems__ to work, until, presumably, it doesn’t. But what, then, is the difference between an atomic<double>* and a normal double*, if the sizes (and possibly alignments) are the same? Hmmm, I just read up on what a reinterpret_cast<> is supposed to be good for, which is very little indeed, so it seems that the behaviour is undefined - but then there is no way to solve that problem? (So far I only ever used it to print the address of a pointer...) Since openMP allows for a pragma atomic, somehow, it seems that there should be a way. Using a simple spin_lock is way too slow (tested), since it doesn’t lock a specific memory location, but essentially everything, and I suspect that more complicated locking schemes will be also more expensive, just for different reasons. Ben Thanks for your insight! Tim

2 1

[atomic] can it bechecked that boost::atomic<T> *v = reinterpret_cast<boost::atomic<T>*>(var); is safe?
by Tim Odenthal 15 Sep '14

15 Sep '14

Dear experts, essentially, I use this type of reinterpret_cast for doubles, and it __seems__ to work fine. I compile-time check that the sizeof(boost::atomic<T>) == sizeof( T ), but is that enough to ensure that this will always work? Should/could I check alignment issues as well? Even if the "atomic_cast" function has a (small) run-time overhead, it would be very much worth it in my setting, where I actually want to safely add to a double at some location in memory. Obviously, I want to use boost::atomic to be system/compiler agnostic, since it's supposed to eventually run with clang, gcc, (linux, OS X) as well as MS compilers, and so far we didn't see the need to move to C++11... Thanks for any advice in advance Tim

2 1

program_options Parsing Suboptions
by Robert 15 Sep '14

15 Sep '14

Hi, I am trying to use program_options to parse suboptions: Command –S “-a 1 –b test –c 1.2” (the suboptions in –S are to be passed into other programs) Using the example source code, I tried something like the code below, but get the following error The argument (‘ 1’) for option ‘—TestA’ is invalid. Apparently the space between –a and 1 is treated as part of the argument and thus will not convert to an integer. I tried at the top argument level (e.g. command –M 1) and it works as expected, so something about creating the vector of suboptions is confusing program_options. Any suggestions? Thanks very much. options_description desc("Allowed options"); desc.add_options()("subopt,S",value<string>(),"Sub Options"); variables_map vm; store(command_line_parser(ac, av).options(desc).run(), vm); vm.notify(); if (vm.count("subopt")) { string substring=vm["subopt"].as<string>(); boost::regex re("\\s+(?=-)"); boost::sregex_token_iterator i(substring.begin(), substring.end(), re, -1); boost::sregex_token_iterator j; vector<string> splitResults; copy(i,j,back_inserter(splitResults)); int ta; string tb; float tc; options_description subopt_desc("Suboptions"); subopt_desc.add_options() ("TestA,a", value<int>(&ta)->default_value(0), "integer") ("TestB,b",value<string>(&tb),"string") ("TestC,c",value<float>(&tc), "float") ; variables_map subopt_vm; store(command_line_parser(splitResults).options(subopt_desc).run(), subopt_vm); subopt_vm.notify(); cout<<"a="<<ta<<endl; cout<<"b="<<tb<<endl; cout<<"c="<<tc<<endl; } -- http://www.fastmail.fm - Choose from over 50 domains or use your own

1 1

[graph] how to find all vertices reachable from one edge of a starting vertex
by Michael Marcin 14 Sep '14

14 Sep '14

How can I find all vertices reachable by following one specified out-edge? Is there already an algorithm that does this? If not I think I could do it by: - marking all vertices white - mark starting vertex gray - depth_first_visit the target of the specified edge Does this work?

2 2

[container][slist] constant time splice_after
by Aaron Levy 14 Sep '14

14 Sep '14

What happens if I call slist::splice_after(this_iter, that_list, that_begin, that_end, nelems) with an nelems value that does not match std::distance(that_begin, that_end). In other words, is there any kind of validations performed on nelems and is it just used to update the size of the list? Aaron

2 1

how to construct an iterator_archetype<single_pass_traversal_tag>
by Peter Johansson 13 Sep '14

13 Sep '14

Hi, I'm writing tests using the iterator_archetype [http://www.boost.org/doc/libs/1_55_0/libs/iterator/doc/iterator_archetypes.…] and get confused how to use a single_pass_iterator such as e.g. iterator_archetype<int, readable_iterator_t, single_pass_iterator> The default constructor does not work as expected (since single_pass_iterators are not necessarily default constructible). The copy constructor is not very useful and that is all can find. I noticed the detail::ctor_arg and was hoping there were a constructor thaing that struct as argument - but no. How am I supposed to construct this class if I e.g. wanna passed it to a function that I intend to test. Thank you, Peter

1 0

[container][flat_map] Internal storage for flat_maps / flat_sets
by Aaron Levy 13 Sep '14

13 Sep '14

What is the type of the underlying contiguous storage used by the flat_map / flat_set containers? Does the following code make sense: flat_map<T> container; ... if (container.size() > 0) { const T& elem = *(container.begin()); const T& elem_1 = *(container.begin() + 1); assert(&elem_1 == &elem + 1); } Aaron

2 1

Problem linking with boost::program_options with clang 3.5 (OSX)
by Jürgen Simon 12 Sep '14

12 Sep '14

Hello, I require OpenMP on OSX and had to build OpenMP/Clang to that end. The compiler reads as clang 3.5. For some reason, the compiler seems to have a problem linking executables with boost. I tried boost version 1.55 but got a compilation error. Boost 1.56 compiles with this warning: clang-3.5: warning: argument unused during compilation: '-finline-functions' but other than that compiles through and installs just fine. When trying to link an executable with program_options however, I get the following linker error: Undefined symbols for architecture x86_64: "__ZN5boost15program_options11to_internalERKSs", referenced from: __ZN5boost15program_options11to_internalISsEESt6vectorISsSaISsEERKS2_IT_SaIS5_EE in radolan2cf.cpp.o "__ZN5boost15program_options19options_descriptionC1ERKSsjj", referenced from: _main in radolan2cf.cpp.o "__ZN5boost15program_options20invalid_option_valueC1ERKSs", referenced from: __ZN5boost15program_options8validateIfcEEvRNS_3anyERKSt6vectorISbIT0_St11char_traitsIS5_ESaIS5_EESaIS9_EEPT_l in radolan2cf.cpp.o "__ZN5boost15program_options22error_with_option_nameC2ERKSsS3_S3_i", referenced from: __ZN5boost15program_options16validation_errorC2ENS1_6kind_tERKSsS4_i in radolan2cf.cpp.o "__ZN5boost15program_options6detail7cmdline21set_additional_parserENS_9function1ISt4pairISsSsERKSsEE", referenced from: __ZN5boost15program_options25basic_command_line_parserIcE12extra_parserENS_9function1ISt4pairISsSsERKSsEE in radolan2cf.cpp.o "__ZN5boost15program_options6detail7cmdlineC2ERKSt6vectorISsSaISsEE", referenced from: __ZN5boost15program_options25basic_command_line_parserIcEC2EiPKPKc in radolan2cf.cpp.o "__ZN5boost15program_options8validateERNS_3anyERKSt6vectorISsSaISsEEPSsi", referenced from: __ZNK5boost15program_options11typed_valueISscE6xparseERNS_3anyERKSt6vectorISsSaISsEE in radolan2cf.cpp.o "__ZN5boost15program_optionslsERSoRKNS0_19options_descriptionE", referenced from: _main in radolan2cf.cpp.o "__ZNK5boost15program_options22abstract_variables_mapixERKSs", referenced from: __ZNK5boost15program_options13variables_mapixERKSs in radolan2cf.cpp.o "__ZNK5boost15program_options22error_with_option_name23substitute_placeholdersERKSs", referenced from: __ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options20invalid_option_valueEEEEE in radolan2cf.cpp.o __ZTVN5boost16exception_detail19error_info_injectorINS_15program_options20invalid_option_valueEEE in radolan2cf.cpp.o __ZTVN5boost15program_options20invalid_option_valueE in radolan2cf.cpp.o __ZTVN5boost15program_options16validation_errorE in radolan2cf.cpp.o __ZTVN5boost16exception_detail10clone_implINS0_19error_info_injectorINS_15program_options16validation_errorEEEEE in radolan2cf.cpp.o __ZTVN5boost16exception_detail19error_info_injectorINS_15program_options16validation_errorEEE in radolan2cf.cpp.o "__ZNK5boost15program_options29value_semantic_codecvt_helperIcE5parseERNS_3anyERKSt6vectorISsSaISsEEb", referenced from: __ZTVN5boost15program_options11typed_valueIfcEE in radolan2cf.cpp.o __ZTVN5boost15program_options11typed_valueISscEE in radolan2cf.cpp.o ld: symbol(s) not found for architecture x86_64 clang-3.5: error: linker command failed with exit code 1 (use -v to see invocation) I’m a little stumped as to how to fix this problem. Can someone help me out? Kind Regards, Jürgen

1 0

[Range] Strange!
by Robert Jones 10 Sep '14

10 Sep '14

Can anyone explain why my last output line is garbage? #include <iostream> #include <boost/range/algorithm/copy.hpp> #include <boost/range/counting_range.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/phoenix/bind/bind_function.hpp> #include <boost/phoenix/core/argument.hpp> int doubled( int i ) { return i * 2; } template <typename Range> void print_it( const Range & range ) { boost::copy( range, std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::phoenix::arg_names::_1; print_it( counting_range( 1, 5 ) ); print_it( counting_range( 1, 5 ) | reversed ); print_it( counting_range( 1, 5 ) | transformed( doubled ) ); print_it( counting_range( 1, 5 ) | reversed | transformed( doubled ) ); print_it( counting_range( 1, 5 ) | transformed( bind( doubled, _1 ) ) ); print_it( counting_range( 1, 5 ) | reversed | transformed( bind( doubled, _1 ) ) ); } Output is 1 2 3 4 4 3 2 1 2 4 6 8 8 6 4 2 2 4 6 8 -711713824 -711713824 -711713824 -711713824 Compiling with gcc-4.9.1, Boost 1.56 on Fedora 20 64-bit. Thx, Rob.

6 16

[filesystem] directory_iterator and filter in 1.56.0
by Braden McDaniel 10 Sep '14

10 Sep '14

This sort of thing worked in Boost 1.55.0: #include <boost/filesystem.hpp> #include <boost/range.hpp> #include <boost/range/adaptor/filtered.hpp> struct pred { bool operator()(const boost::filesystem::directory_entry & dirent) const { return true; } }; int main() { const auto dirent_range = boost::make_iterator_range(boost::filesystem::directory_iterator("/"), boost::filesystem::directory_iterator()); const auto filtered_dirent_range = boost::adaptors::filter(dirent_range, pred()); } Not so in 1.56.0 [output from Apple's clang 3.4]: boost/concept_check.hpp:210:9: error: no viable conversion from 'boost::single_pass_traversal_tag' to 'boost::forward_traversal_tag' Y y = x; ^ ~ The full error output is much more verbose and I can provide it if desired; but the above is the gist of the situation, as I understand it: directory_iterators are SinglePass iterators; filter operates on ForwardTraversal iterators; and the SinglePass iterator cannot be converted to the ForwardTraversal one. Is this situation deliberate or an unintended side effect? Is there some similarly succinct means of filtering a file/directory listing? -- Braden McDaniel <braden(a)endoframe.com>

1 0

Re: [Boost-users] [context] Compiling error with context and bind
by José 10 Sep '14

10 Sep '14

3 2

[context] Compiling error with context and bind
by José 09 Sep '14

09 Sep '14

2 1

[msm] extending msm::back::state_machine
by Manuel Schiller 09 Sep '14

09 Sep '14

Hi, I tried to enhance the backend of boost::msm by inheriting from boost::msm::back::state_machine. When doing so, I cannot access members of my subclass in the states. When compiling the attached example, I get this error message: *error: ‘class boost::msm::back::state_machine<fsm_, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>’ has no member named ‘test’* How can I "inject" extended_back_machine as the type being passed as "FSM" to the state? Bye Manuel #################################### template<typename FrontMachine> struct extended_back_machine : public boost::msm::back::state_machine<FrontMachine> { void test() { std::cout << "test" << std::endl; } }; struct fsm_ : public boost::msm::front::state_machine_def<fsm_> { struct State : public boost::msm::front::state<> { template <class Event,class FSM> void on_entry(Event const&, FSM& fsm) { fsm.test(); } }; typedef State initial_state; }; int main() { typedef extended_back_machine<fsm_> fsm; fsm m; m.start(); return 0; } ####################################

3 3

[boost][container][static_vector] Stack or heap?
by Aaron Levy 08 Sep '14

08 Sep '14

Does the boost::container::static_vector allocate its memory on the stack or heap. From what I could make of the code, it seems to allocate on the stack. What happens if the requested size exceeds the stack size limits? Aaron

2 1

[boost][assign][bimap] Assign support for bimap
by Aaron Levy 08 Sep '14

08 Sep '14

Are there any Boost.Assign overloads available for Boost.Bimap? Aaron

2 2

linking with Intel compiler to Boost libs compiled with Visual Studio
by Damien 05 Sep '14

05 Sep '14

Hi, I'm trying to link to Boost 1.56 libs that I built with VS2013. We compile with both Intel and VS. We build Boost with layout=tagged (e.g. boost_serialization-mt-gd.lib), and these link fine with VS2013. When linking with Intel 2015 the linker complains about a missing library, looking for the layout=versioned lib name (e.g. libboost_serialization-iw-mt-gd-1_56.lib). Even if you specify the library name directly on the link line, it still complains. I'm sure this is just an include or #define issue but I don't know where to look. If anyone can point me in the right direction I'd be grateful. Cheers, Damien

2 2

Testers required
by Antony Polukhin 05 Sep '14

05 Sep '14

Hi, There is a big need in testers that have access to exotic platforms(zArch, MIPS) and compilers (Cray, IBM xlc ...). Could you please run `b2` in `boost/libs/type_index/test` and report results. This will help to test Boost.TypeIndex library and other libraries that depend on `demangle.hpp` I'll appreciate any help. Thanks in advance! -- Best regards, Antony Polukhin

1 0

[graph] Vertex order and VertexList type changes boykov_kolmogorov_max_flow result
by Michael J Iatauro 04 Sep '14

04 Sep '14

In the code below, using listS to store vertices results in vertex instantiation order changing the amount of flow computed by boykov_kolmogorov_max_flow. As given, it computes a flow of 0. If I move the instantiation of "T-" to be before "t-" or switch the VertexList parameter of adjacency_list to vecS, it computes the correct flow of 1000. Stepping through the code, it looks like when the max_flow function iterates over vertices that are targets of out-edges from the source, the call to get(m_in_active_list_map, v) at boykov_kolmogorov_max_flow.hpp:528 returns true for the second vertex, preventing it from getting added to m_active_nodes. I tested this using g++ 4.4.7 and with Boost 1.55 and 1.56. Has anybody else seen anything like this? Code follows: #include <boost/graph/adjacency_list.hpp> #include <boost/graph/boykov_kolmogorov_max_flow.hpp> #include <boost/graph/properties.hpp> #include <boost/graph/graph_traits.hpp> #include <iostream> #include <limits> using namespace boost; typedef adjacency_list_traits<vecS, listS, directedS> Traits; typedef Traits::vertex_descriptor Vertex; typedef Traits::edge_descriptor Edge; typedef adjacency_list<vecS, listS, directedS, property<vertex_name_t, std::string, property<vertex_index_t, long, property<vertex_color_t, default_color_type, property<vertex_distance_t, long, property<vertex_predecessor_t, Edge > > > > >, property<edge_flow_t, double, property<edge_capacity_t, double, property<edge_residual_capacity_t, double, property<edge_reverse_t, Edge > > > > > Graph; void addEdge(Graph& g, const Vertex& source, const Vertex& target, const double capacity, const double reverseCapacity) { property_map<Graph, edge_reverse_t>::type rev = get(edge_reverse, g); Edge e1 = add_edge(source, target, g).first; Edge e2 = add_edge(target, source, g).first; put(edge_capacity, g, e1, capacity); put(edge_capacity, g, e2, reverseCapacity); rev[e1] = e2; rev[e2] = e1; } int main(void) { Graph g; property_map<Graph, vertex_name_t>::type nameMap = get(vertex_name, g); Vertex source = add_vertex(g); nameMap[source] = "source"; Vertex sink = add_vertex(g); nameMap[sink] = "sink"; Vertex tminus = add_vertex(g); nameMap[tminus] = "t-"; addEdge(g, source, tminus, 1, 0); Vertex Tminus = add_vertex(g); nameMap[Tminus] = "T-"; addEdge(g, source, Tminus, 1000, 0); Vertex Tplus = add_vertex(g); nameMap[Tplus] = "T+"; addEdge(g, Tplus, sink, 1000, 0); addEdge(g, Tplus, Tminus, 0, std::numeric_limits<int>::max()); double flow = boykov_kolmogorov_max_flow(g, source, sink); std::cout << flow << std::endl; return 0; } -- ------------------ Michael J. Iatauro Software Engineer QTS, Inc. NASA Ames Research Center Office: 650-604-0662 Mail stop: 269-2 P.O. Box 1 Moffett Field, CA 94035-0001

1 0

Batch job processing with Boost Spirit parser
by Michael Levine 04 Sep '14

04 Sep '14

I have been using Boost Sprit as a parser for a project that I have been working on lately. At this point, I have been trying to expand the software and, in doing so, have had the nagging feeling that there is something wrong with my overall design. In the best case, I am not making the best use of my tools, and in the worst case, I am concerned that the design/code is becoming overly brittle. As an aside, I don’t have a huge amount of programming experience with this type of application. A word of background / context : Essentially, the program performs batch ‘jobs’ which are specified in a text file (not dissimilar in that sense from a scheduler like Condor). Spirit parses these ‘Job Description’ files into ‘specification objects’ (my vocabulary) that are used with a builder pattern and factories to create the appropriate objects. I have some concerns about this which I will describe later. The job description (henceforth: JD) file should have 3 parts: 1. Data 2. Tools 3. Operations The Data section is just a list of data that is to be operated on. At this stage, this is just a vector of std::pair<std::string, std::string> containing an identifier and the path of the file. The ‘Tools’ and ‘Operations’ sections are likely composed of nested specifications (the resulting objects use either a decorator pattern or composite pattern – depending on the type of tool) – which was the main reason that I started using Spirit altogether. My question is really a request for some guidance – to better utilize the tools available: I have just received the requirement for section #3 (Operations), to be included in the JD file (previously it was assumed that this would be provided in a different manner). So – at this time, I have a working parser for the Data and Tools portions. I have concerns with the ‘Tools’ portion that I would like to correct and not duplicate in the ‘Operations’ section that I am to be working on next. At present, I am parsing the JD file mostly into strings, and vectors of boost::variant<int,double> -- the latter being a list of parameters in a completely arbitrarily imposed order. As I’ve previously mentioned, I have a few problems with this approach. - The parameters are required to be input in an arbitrary order. - Different ‘Tool’s and ‘Operation’s have different parameters that are required and/or optional. For the past weeks (I only work on this project on a very part-time basis), I have been going in circles trying to figure out a better way to do this. I have a strong suspicion that Fusion can be used for this. I am also concerned about over-complicating the design, but am weary of leaving the design too simplistic. I.e., I know that I can treat the parameters as a std::pair<std::string, boost::variant<int, double>> and then parse key-value pairs with a given delimiter. I am just not convinced that this is the best way to do this. I am able to use any Boost Library, and have no restrictions about compilers (I’m using a recent version of Clang, primarily, right now). The following is a selection of the data structures and Spirit grammar that I am using here: struct Tool_Spec; typedef std::vector<boost::variant<int, double> > Tool_Options_t; typedef std::vector<Tool_Spec > Children_Tool_t; typedef std::pair<std::string, std::string> Data_Spec; struct Job_Request { Data_Spec data_spec; Tool_Spec model_spec; Operation_Spec operation_spec; boost::optional<std::string> description; }; struct Tool_Spec{ std::string type; std::string data_designation; Tool_Options_t; options; Children_Tool_t children; boost::optional<std::string> designation; }; struct Operation_Spec{ /* Unknown at this time. Need help */ }; Datafile %= lit("@START") >> *Data_Description >> Tool_Description >> Operation_Description >> lit("@END") ; Data_Description %= lit('%') >> Datasource >> lit(';') ; Datasource = Designator >> lit(':') >> Designator ; Designator %= +(char_("0-9a-zA-Z/._") | char_('-') ); Comment_Designator %= +(char_("0-9a-zA-Z/._, ()") | char_('-')); Tool_Description %= Designator >> ':' >> ('@' >> Designator) >> '[' >> +Options >> ']' >> -('{' >> *Child_Tool >> '}') >> -qi::lexeme[Comment_Designator] >> ';' ; Child_Tool %= Designator >> ':' >> ('@' >> Designator) >> '[' >> +Options >> ']' >> -('{' >> *Child_Tool >> '}') >> -qi::lexeme[Comment_Designator] >> ';' ; Options %= (int_ | double_ ) % '|';

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