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[asio] multiple simultaneous async_read calls
by bbxiong 11 Aug '14

11 Aug '14

Hello, all, If i write some code like this: boost::asio::async_read(socket_, bosot::asio::buffer(buffer1_.data(), len1, handler1); boost::asio::async_read(socket_, boost::asio::buffer(buffer2_.data(), len2, handler2); Will asio guarantee len1 bytes received by the first async_read, then schedule async_read2? or the result is undefined(like several bytes filled into buffer1, then next several bytes into buffer, then next several bytes into buffer1)? if the result is undefined, why asio don't add a check here? Thanks all in advance!

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[Boost.Thread] Compile error: boost::promise<T>::set_value(const T&) doesn't exist
by Rob Desbois 10 Aug '14

10 Aug '14

Hi all, I'm having problems compiling with Boost.Thread's futures I can't seem to pass anything but a primitive type into make_ready_future. I've had problems with other parts of Thread (packaged_task, promise, unique/shared_future) that have produced horrendously unhelpful compile errors. Here is a minimal testcase: #include <boost/thread/future.hpp> struct foo { foo(int i_): i(i_) {} int i; }; int main() { // A const future ref isn't much use, but I needed to prove // the problem wasn't me trying to copy a unique_future const boost::unique_future<foo>& fut = boost::make_ready_future( foo(42) ); } With `BOOST_THREAD_USES_MOVE` defined before including the Boost.Future header I get the following error with gcc 4.8.2 and Boost 1.55 (full output at http://pastebin.com/0sePWBWr) ../../deps/boost/include/boost/thread/future.hpp:3634:5: error: no matching function for call to ‘boost::promise<foo>::set_value(const foo&)’ p.set_value(boost::forward<future_value_type>(value)); ^ There seems to be no overload of promise::set_value() that takes a const lvalue reference. Looking at `promise` and `future_traits` in `future.hpp` it seems that the const lvalue ref overload will only exist when `BOOST_NO_CXX11_RVALUE_REFERENCES` is undefined. That makes no sense to me however...surely the const lvalue ref overload is needed precisely when there are no rvalue references? (Note this happens even if I pass a mutable lvalue ref to `make_ready_future()`). If I don't define `BOOST_THREAD_USES_MOVE` it fails compilation with the following error (full output at http://pastebin.com/jBwiJLeC) ../../deps/boost/include/boost/thread/detail/move.hpp:183:54: error: no matching function for call to boost::unique_future<foo>::unique_future(boost::unique_future<foo>)’ #define BOOST_THREAD_MAKE_RV_REF(RVALUE) RVALUE.move() ^ Have I missed something? I'm unable to switch to C++11 mode unfortunately, but this seems such a big problem I can only assume I've done something wrong. I still get similar compile errors trying with Clang 3.4, and also with Boost 1.54 (g++ or Clang). -- Rob Desbois http://theotherbranch.wordpress.com/

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[Boost.Range] Filtering elements at even position
by Arindam Mukherjee 10 Aug '14

10 Aug '14

I am trying to create a range consisting of elements in a container at only even indexes. Is there a way to write something like: vec | boost::adaptors::indexed(0) | some_adaptor_to_choose_even_indexes I tried with boost::adaptors::filtered, but the index information is only present in iterators of the generated range, not in its value_type so it is not available in chained adaptors. - Arindam

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Boost 1.56.0 compilation error in iterator_range
by gast128 10 Aug '14

10 Aug '14

I get a compilation error with vc10, iterator_range and a (const) unordered_map (the beta candidate 2 was still ok I think): #include "stdafx.h" #include <boost/range/iterator_range.hpp> #include <boost/unordered_map.hpp> int _tmain(int /*argc*/, _TCHAR* /*argv*/[]) { typedef boost::unordered_map<int, int> Container; typedef Container::const_iterator ContainerIterator; typedef boost::iterator_range<ContainerIterator> ContainerIteratorRange; const Container cnt; ContainerIteratorRange rng(cnt.cbegin(), cnt.cend()); return 0; } This gives C2248: 'boost::unordered::iterator_detail::c_iterator<Node,ConstNodePointer>::iterator' cannot access private typedef declared in class etc. (note had to cut due to 'you have lines longer than 80 characters. Fix that.' in Gmane)

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[boost] [1.55] numerous warnings with gcc 4.8.3 on Linux
by Marius Lazer 08 Aug '14

08 Aug '14

All the warnings are similar to this (warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs]): ./boost/range/algorithm/equal.hpp: In function âbool boost::range::equal(const SinglePassRange1&, const SinglePassRange2&, BinaryPredicate)â: ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check185â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ^ ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:185:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange1> )); ^ ./boost/concept/detail/general.hpp:71:20: warning: typedef âboost_concept_check186â locally defined but not used [-Wunused-local-typedefs] BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/preprocessor/cat.hpp:29:34: note: in definition of macro âBOOST_PP_CAT_Iâ # define BOOST_PP_CAT_I(a, b) a ## b ./boost/concept/detail/general.hpp:71:7: note: in expansion of macro âBOOST_PP_CATâ BOOST_PP_CAT(boost_concept_check,__LINE__) ^ ./boost/concept/assert.hpp:44:5: note: in expansion of macro âBOOST_CONCEPT_ASSERT_FNâ BOOST_CONCEPT_ASSERT_FN(void(*)ModelInParens) ^ ./boost/range/concepts.hpp:92:45: note: in expansion of macro âBOOST_CONCEPT_ASSERTâ #define BOOST_RANGE_CONCEPT_ASSERT( x ) BOOST_CONCEPT_ASSERT( x ) ^ ./boost/range/algorithm/equal.hpp:186:13: note: in expansion of macro âBOOST_RANGE_CONCEPT_ASSERTâ BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange2> )); Thanks, Marius Marius S. Lazer ICAP North America Inc. Harborside Financial Center 1100 Plaza 5 Jersey City, NJ 07311-4996 Office: 212-815-7470 Email: Marius.Lazer(a)us.icap.com ********************************************************************** This communication and all or some of the information contained therein may be confidential and is subject to our Terms and Conditions. If you have received this communication in error, please destroy all electronic and paper copies and notify the sender immediately. Unless specifically indicated, this communication is not a confirmation, an offer to sell or solicitation of any offer to buy any financial product, or an official statement of ICAP or its affiliates. Non-Transactable Pricing Terms and Conditions apply to any non-transactable pricing provided. All terms and conditions referenced herein available at www.icapterms.com. Please notify us by reply message if this link does not work. ********************************************************************** ICAP's 21st global annual Charity Day – took place Tuesday 3 December 2013. Together we raised £9.5 million (US$15.5 million), totalling £110 million since 1993. www.icapcharityday.com --------------------------------------------------------------------------------------- This email has been scanned for email related threats and delivered safely by Mimecast. For more information please visit http://www.mimecast.com ---------------------------------------------------------------------------------------

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BOOST_STRONG_TYPEDEF
by Jono Poff 08 Aug '14

08 Aug '14

Hi, compiling this program with g++ 4.7.1 ... #include <boost/serialization/strong_typedef.hpp> BOOST_STRONG_TYPEDEF(uint32_t, LINKID_T) int main() { LINKID_T lid = 0xffddee33; return 0; } I get error: conversion from 'unsigned int' to non-scalar type 'LINKID_T' requested Looking at the header, the strong typedef struct defines assignment from uint32_t to LINKID_T ... D & operator=(const T & rhs) { t = rhs; return *this;} ... so what gives? Cheers, Jono -- ------------------------------ This email, including any attachments, is only for the intended recipient. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If you are not an intended recipient, you may not use, disseminate, distribute or reproduce such email, any attachments, or any part thereof. If you have received a message in error, please notify the sender immediately and erase all copies of the message and any attachments. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission nor can we guarantee that any email or any attachments are free from computer viruses or other conditions which may damage or interfere with recipient data, hardware or software. The recipient relies upon its own procedures and assumes all risk of use and of opening any attachments. ------------------------------

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BOOST_STRONG_TYPEDEF ...ps
by Jono Poff 08 Aug '14

08 Aug '14

Sorry, forgot to say Boost 1.55.0 Jono -- ------------------------------ This email, including any attachments, is only for the intended recipient. It is subject to copyright, is confidential and may be the subject of legal or other privilege, none of which is waived or lost by reason of this transmission. If you are not an intended recipient, you may not use, disseminate, distribute or reproduce such email, any attachments, or any part thereof. If you have received a message in error, please notify the sender immediately and erase all copies of the message and any attachments. Unfortunately, we cannot warrant that the email has not been altered or corrupted during transmission nor can we guarantee that any email or any attachments are free from computer viruses or other conditions which may damage or interfere with recipient data, hardware or software. The recipient relies upon its own procedures and assumes all risk of use and of opening any attachments. ------------------------------

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Geometry layout (packing) algorithm?
by Belcourt, Kenneth 07 Aug '14

07 Aug '14

Hi, I’m looking for an algorithm that will take a largish number (i.e. 10^5) 2d or 3d polygons (mostly parallel-pipeds, e.g. squares and boxes) and partition them into non-overlapping groups where each group contains some number of polygons that might abut along an edge or face, but not overlap. Each box can be represented by a collection of line segments so I thought geometry might have what I’m looking for but I didn’t see anything in a quick scan of the documentation. Does this so called packing (layout) algorithm sound like something already in Boost, Geometry or other library? I have an implementation but what looking to see what other options exist. Thanks. — Noel Belcourt

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[boost] [1.56.0] Release Candidate 3 available
by Marshall Clow 07 Aug '14

07 Aug '14

We've created a third release candidate to fix a one more issue with Boost.Range. The files for 1.56.0 RC3 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. The files (and associated md5s) are: MD5 (./boost_1_56_0_rc3.7z) = b7a72a6a6f487fa445333b4e115c6171 MD5 (./boost_1_56_0_rc3.tar.bz2) = a744cf167b05d72335f27c88115f211d MD5 (./boost_1_56_0_rc3.tar.gz) = 8c54705c424513fa2be0042696a3a162 MD5 (./boost_1_56_0_rc3.zip) = fc16da21d641e03715a4144cb093964e Thanks! -- The release managers

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[date-time] boost::time_duration wrapping
by Justin Muncaster 07 Aug '14

07 Aug '14

Hello, I’m having issues with wrapping of boost::time_duration derived types. I can’t find anywhere in the documentation for when the time_duration types are supposed to wrap around. I have attached some sample source code below. The output is: SecCount = 80000000 is OK. Strange Stranger Problematic SecCount = 80000001 is STRANGE. I expect the output to be SecCount = 80000000 is OK. SecCount = 80000001 is OK. The problem we ran into had to do with seconds and milliseconds having different maximum permissible values. Any idea why boost::posix_time::seconds goes negative at 0x80000001 while milliseconds is not until much later? Thanks, Justin // // test.cpp // #include <boost/date_time.hpp> #include <iostream> using namespace std; using namespace boost::posix_time; //------------------------------------------------------- //------------------------------------------------------- void Strange(long SecCount) { long MilliCount = 1000 * SecCount; bool IsStrange = false; if (SecCount >= 0 && seconds(SecCount).is_negative()) { cout << "Strange" << endl; IsStrange = true; if (!milliseconds(MilliCount).is_negative()) { // If seconds wraps, why doesn't milliseconds? cout << "Stranger" << endl; IsStrange = true; } } if (seconds(SecCount) != milliseconds(MilliCount)) { cout << "Problematic" << endl; IsStrange = true; } if (!IsStrange) { cout << "SecCount = " << SecCount << " is OK." << endl; } else { cout << "SecCount = " << SecCount << " is STRANGE." << endl; } } //------------------------------------------------------- //------------------------------------------------------- int main() { cout << hex; Strange(0x80000000); Strange(0x80000001); return 0; }

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Re: [Boost-users] [ASIO] directory monitor ASIO extension
by Brian Wood 06 Aug '14

06 Aug '14

Niall Douglas writes > * Works reliably on Microsoft Windows (hard), Linux (slightly > easier), BSD and OS X (easiest by far of the lot). > I believe you. Having considered some of your previous comments in a different thread, on kqueue, I ported my code generator from Linux to BSD. I only found relief from a problem I was having by doing so. > Paul Kirth presented on this at C++ Now 2014. It is a surprisingly > tough engineering problem, and requires a design approaching ideal > for it to work at all. Are videos from that conference available yet? -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[ASIO] directory monitor ASIO extension
by Szymon Gatner 06 Aug '14

06 Aug '14

Hi, I am going through code of directory monitor ASIO extension by Boris Schäling (http://www.highscore.de/boost/dir_monitor.zip) and I am wondering: what is the benefit of making this piece of code / library an ASIO extension. It just feels like it could be easier to use and implement if it wasn't? I hope I am missing something tho and looking here for enlightenment ;) Regards, Szymon Gatner

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why lockfree/queue.hpp requires has_trivial_assign and has_trivial_destructor to template type T
by 何子杰Hzj_jie 06 Aug '14

06 Aug '14

hi, all,as new to boost, i am looking for a solution to combine boost::lockfree::queue with std::function, i.e. boot::lockfree::queue<std::function>, but unfortunately, the implementation of the lockfree queue required the T to be trivial assignable and trivial destructible.with some basic investigation to the implementation of boost::lockfree::queue, the assignment operator is using when pop or unsynchronized_pop, it calls detail::copy_payload, which is using operator= or constructor and operator=. though overloaded assignment operator may use more time and cause the pop function to wait for longer time, i do not see it would block the logic.for the destruction, queue implementation always calls pool.template destruct instead deallocate, which means even for a default destructor, it will also be called. so is this a defect or by-design behavior of the lockfree queue? thank you in advanced. .Hzj_jie

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[msm] State Machine and Dependency Injection
by Kris 05 Aug '14

05 Aug '14

Hi, Recently I have implemented Dependency Injection library, which I proposed to boost last week (http://boost.2283326.n4.nabble.com/is-there-any-interest-in-a-dependency-in…) Right now I wanted to shared how dependency injection might be integrated with Boost.MSM (eUML) and would really glad for any feedback. Boost.MSM is a great library, unfortunately actions/guards have to have empty constructor and whole logic has to be handled via Finite State Machine. Such approach is hard to maintain and test, so would be great to have possibility to implement action/guards without FSM dependency and with proper dependency injection instead. More information: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html/di/examples/int… Hello World: class guard : public euml_action<guard> { public: guard(shared_ptr<data> data = nullptr, shared_ptr<other_data> = nullptr); // default constructor is required by eUML template<typename TEvent> bool operator()(const TEvent&) const; // no FSM dependency }; class action : public euml_action<action> { public: action(shared_ptr<data> data = nullptr, shared_ptr<other_data> = nullptr); // default constructor is required by eUML template<typename TEvent> void operator()(const TEvent&); // no FSM dependency }; class state_machine_ : public state_machine_def<state_machine_> { public: using initial_state = state1; BOOST_MSM_EUML_DECLARE_TRANSITION_TABLE(( state1() + event() [guard()] / action() == state2() ), transition_table) }; using state_machine = back::state_machine< state_machine_ , back::use_dependency_injection // Boost.DI dependency injection policy >; auto sm = di::make_injector().create<state_machine>(); // create state machine / actions, guards and their dependencies will be injected via DI framework sm.process_event(event()); Hot it works? * we do implement actions/guards with any dependencies we need * we add use_dependency_injection policy in state machine definition * we create state machine using dependency injection framework library What MSM with DI actually give us? * actions/guards are really easy to test / code doesn't require FSM dependency - loosely coupled * signature change of actions/guards may not require binding configuration changes (if it's not an interface or it's an interface already bound) * FSM is just a declarative abstraction - we don't need to test it * we can use all DI goods for controlling how dependencies will be injected - see https://github.com/krzysztof-jusiak/di Project (with workings tests): https://github.com/krzysztof-jusiak/msm Comparison between usage of Boost.MSM with DI and without it: http://krzysztof-jusiak.github.io/di/boost/libs/di/doc/html/di/examples/int… Looking forward to hear from you. Any feedback is more than welcome. Cheers, Kris -- View this message in context: http://boost.2283326.n4.nabble.com/msm-State-Machine-and-Dependency-Injecti… Sent from the Boost - Users mailing list archive at Nabble.com.

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[1.56.0] Release candidates available
by Marshall Clow 04 Aug '14

04 Aug '14

Release candidate files for 1.65.0 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: MD5 (boost_1_56_0_rc1.7z) = 0ac22b92b24209286d48e4c41925cd9f MD5 (boost_1_56_0_rc1.tar.bz2) = 5b5bfa99244b1ac5737323decceb19c2 MD5 (boost_1_56_0_rc1.tar.gz) = 2047cdd4e09cda34e7f10fec0f821175 MD5 (boost_1_56_0_rc1.zip) = 0c544f6acc85550b15cdc9221f2ac0c9 Thanks! -- The release managers

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[serialization] Please help me solve this compile error.
by Paul Blampspied 04 Aug '14

04 Aug '14

I am tearing my hair out over this, partly because I believe the code used to compile. I just can't see what the problem is. I enclose all the pertinent code as I cannot say which bits are irrelevant. There are two classes: ManagedArray which is an array of data without size or capacity data (this is stored elsewhere). PersistentManagedArray which I wrote to enable ManagedArrays to be serialized. The error message is produced in 'main': error: no match for 'operator<<' in 'oa << PersistentManagedArray<int>((* & size), (* & capacity), (* & ints))' It seems to me that I have defined the necessary serialize member function with the right signature. Commented out is code I wrote some time ago which used separate load and save functions. This, I believe, used to work. #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <string> using namespace std; //**************************************************************************************************************************** template<class T> class ManagedArray { public: T *values; ManagedArray() { values = NULL; } ~ManagedArray() { if (values) { delete [] values; } } //Changes array size. If array grows, the new values are unintialized. void resize(unsigned oldSize, unsigned newSize) { if (oldSize==newSize) return; T *newValues = (newSize==0) ? NULL : new T[newSize]; if (oldSize!=0) { T *oldValue, *newValue; T *end = values + (oldSize<newSize ? oldSize : newSize); for(oldValue=values, newValue=newValues; oldValue<end; oldValue++, newValue++) { *newValue = *oldValue; } } if (values) { delete [] values; } values = newValues; } //Changes array size. If array grows, the new values are initialised to copies of a prototype, initValue. void resize(unsigned oldSize, unsigned newSize, T &initValue) { if (oldSize==newSize) return; T *newValues = (newSize==0) ? NULL : new T[newSize]; T *oldValue = values; T *newValue = newValues; if (oldSize!=0) { T *oldEnd = values + (oldSize<newSize ? oldSize : newSize); for(; oldValue<oldEnd; oldValue++, newValue++) { *newValue = *oldValue; } } T *newEnd = newValues + newSize; for(; newValue<newEnd; newValue++) { *newValue = initValue; } delete [] values; values = newValues; } inline T &operator[](unsigned index) { return values[index]; } inline const T &operator[](unsigned index) const { return values[index]; } }; //**************************************************************************************************************************** //This class helps to save a ManagedArray in a Boost archive // Usage: // ar & PersistentManagedArray(size, capacity, array); template<class T> class PersistentManagedArray { public: PersistentManagedArray(unsigned &size, unsigned &capacity, ManagedArray<T> &managedArray) : _size(size), _capacity(capacity), _managedArray(managedArray) {valueArrayExists = (_managedArray.values!=NULL);} private: unsigned &_size; unsigned &_capacity; ManagedArray<T> &_managedArray; bool valueArrayExists; friend class boost::serialization::access; // template<class Archive> // void save(Archive & ar, const unsigned int version) const { // ar & valueArrayExists; // if (valueArrayExists) { // for(unsigned i=0; i<_size; i++) { // ar & _managedArray.values[i]; // } // } // } // template<class Archive> // void load(Archive & ar, const unsigned int version) { // _managedArray.values = NULL; // ar & valueArrayExists; // if (valueArrayExists) { // _managedArray.resize(0, _capacity); // for(unsigned i=0; i<_size; i++) { // ar & _managedArray.values[i]; // } // } // } // BOOST_SERIALIZATION_SPLIT_MEMBER() template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & valueArrayExists; ar & _size; ar & _capacity; if (Archive::is_loading::value) { delete _managedArray.values; _managedArray.values = new T[_capacity]; } for(unsigned i=0; i<_size; i++) { ar & _managedArray.values[i]; } } }; int main(int argc, char *argv[]) { ManagedArray<int> ints; unsigned size; unsigned capacity; string fileName = "data.xxx"; ofstream file(fileName.c_str(), ios::out|ios::binary); if (file.good()) { boost::archive::binary_oarchive oa(file); oa << PersistentManagedArray<int>(size, capacity, ints); //This line does not compile ! } }

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[1.56.0] Release Candidate 2 available
by Eric Niebler 04 Aug '14

04 Aug '14

We've created a second release candidate to fix a few issues. The three fixes since RC1 are listed at the end of this mail. The files for 1.56.0 RC2 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. The files (and associated md5s) are: MD5 (boost_1_56_0_rc2.7z) = 2e1688886aede1c3348e131a0e73a031 MD5 (boost_1_56_0_rc2.tar.bz2) = 2079fabbfb9fb046e6e12e381eff20fa MD5 (boost_1_56_0_rc2.tar.gz) = 96fe9c5f70759399217dc7ee113ecdd3 MD5 (boost_1_56_0_rc2.zip) = df42b60e120841fc3893de7c2529fc4a Thanks! -- The release managers === Changes Since RC1 === Boost.Thread bug is causing coroutine build to fail on gcc 4.6 in C++11 mode. https://github.com/boostorg/thread/pull/21 Boost.Graph broken on MSVC-12 and gcc-4.4. https://github.com/boostorg/graph/pull/14 Boost.System broken on cygwin, local_free_on_destruction not defined. https://github.com/boostorg/system/pull/4

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[MultiIndex] Indexing integers
by Sensei 31 Jul '14

31 Jul '14

Dear all, I am experimenting with MultiIndex, and I am happy with my custom classes. Now I am wondering, can I index integers without a custom class? For instance, say we have a 32 bit unsigned integer, how can I index these with respect to the MSB or LSB? My first guess is using a union, something like union uint32_u { uint32_t data; uint16_t bits[2]; }; // define a multiply indexed set with indices by id and name typedef boost::multi_index::multi_index_container< uint32_u, boost::multi_index::indexed_by< // sort by MSB boost::multi_index::ordered_non_unique<boost::multi_index::member<employee, uint16_t, uint32_u.bits[0]>>, // sort by LSB boost::multi_index::ordered_non_unique<boost::multi_index::member<employee, uint16_t, uint32_u.bits[1]>>, > > integer_set; But I cannot obviously compile it. Is there a way I can do this? Thanks!

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[boost][sync?] "Distributed" value (or something...)
by Klaim - Joël Lamotte 31 Jul '14

31 Jul '14

I would like to ask Boost developers and users: 1. Am I the only one seeing the following pattern in my concurrent systems code? 2. Is there already some tools available in Boost that does what I describe here and that I am not aware of? 3. If not, would there be any interest in the tool I'm describing here or not? Is it a dumb idea? (I keep getting back to this idea but I'm surprised not finding anything similar online) The pattern that I am seeing occurs when: 1. I have a value or a set of values in an object or several objects which value(s) describe some kind of configuration that several other systems will read and use. 2. The object(s) will be updated only by one thread (at a time). 3. When the object's value is modified, all the systems that rely on the object's value have to be notified so that they update themselves using that value. 4. The systems I am refering to can use different threads for updating and we can assume that they are running concurrently. 5. It is not important that the source object's value is synched with the reader's values at all time, however it is important that the sequence of changes to the source object's value is signaled to the readers exactly in the same order and "as fast as possible", but delay is ok. The simplest solution to solve this is to have a mutex locking the value and the systems checking the value regularly. (that is, using syncrhonized_value for example) However the locking and looping reads might not be necessary if it is done in another way (if I am correct, I still lack experience in the domain). The solution that I am thinking about would look like this. ///////// // The object containing the value used by the other systems. class System_A { distributed_source<int> m_foo_count; // changes to this object will be sent to "readers"... public: System_A() : m_foo_count(42) ... {} //... // thread-safe read-only access distributed_value<int> make_foo_count_reader() const { return distributed_value<int>{ m_foo_count }; } }; ///////// // The different systems acquire a read access to the value. class System_B { distributed_value<int> foo_count; // read-only value reflecting System_A::m_foo_count's value since last update. public: SystemB( const System_A& system_a, ... ) : m_foo_count( system_a.make_foo_count_reader() ) { // setup the initial config... on_foo_count_changed( *m_foo_count ); // trigger some processing when SystemA::foo_count's value have been changed: m_foo_count.on_changed( [this]( int new_value ){ // called after the value have been changed m_work_queue.push( [=]{ // will be executed on the next update cycle for this system... on_foo_count_changed( new_value ); / }); }); } //... private: void update_cycle( const UpdateInfo& info ) { // ... // the following is just to clarify: const int foo_before = *m_foo_count; // the value is not updated yet, but we can still use it m_work_queue.execute(); const int foo_after = *m_foo_count; // the value might have been udpated if( foo_before != foo_after ) { // the value have been updated (though you don't need to do this if you used the callback instead). } //... }; }; //////// // At some point the value is changed by the system owning the source object... System_A::change_foo( int new_value ) { m_work_queue.push( [=]{ // will be executed on the next update cycle of this system... // ... *m_foo_count = new_value; // assign the new value then send the new value to the readers... }); } System_A::something_complex( std::function<void(int&)> some_work ) { m_work_queue.push( [=]{ // ... m_foo_count.update( some_work ); // execute on the current value then send the resulting value to the readers }); } Some notes: a. The names are just invented while I write this email. b. I suppose that the distributed_source might have an interface similar to synchronized_value, anyway I didn't get farther than this idea. c. I see several different ways to implement this idea, some might be more efficient than others but I didn't do any tests yet (by lack of time). Thoughts?

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Re: [Boost-users] [MSM] how to use a compilation firewall around inner state machines
by Mark.Bartosik＠thomsonreuters.com 31 Jul '14

31 Jul '14

Repost from different email client (prior ate linefeeds, sorry again). I have a state machine implemented with MSM (eUML) that currently has 80 transitions, there are two inner state machines. Compilation time is not great, but I have been dealing with it by BOOST_MSM_FAVOR_COMPILE_TIME and using parallel compilation where possible. Slow compilation time is an irritation and productivity killer, but my larger worry is that eventually the compiler will run out of memory. Especially as I will likely have to add another inner state machine with about 40 more transitions. Current we are using VS2008 but planning on moving everyone in the team to the VS2012 toolset but running under the VS2013 environment. I don't know if this will help, I doubt it. Currently compilation memory usage is up to 2.5GB per translation unit. So I would like to use a compilation firewall around the inner state machines. My plan is to implement concrete types for the inner state machines, with a process_event function: boost::msm::back::HandledEnum process_event( const boost::any & event ); Then within this function test for each event type to be handled by the inner state machine, and forward to a regular MSM state machine contained within the inner concrete type. I am hoping that this, plus on_entry and on_exit functions is about all I need to do. I expect that I will be able to get this to work, although an example on how to put a concrete wrapper around an inner state machine would be great, and importantly a list of limitations and work arounds for this technique would be helpful. My problem is that the outer state machine transition table has rows like this: exit_pt_( inner_state, inner_state_some_pseudo_exit_state ) / do_some_stuff() == outer_s2, exit_pt_( inner_state, inner_state_other_pseudo_exit_state ) / do_other_stuff() == outer_s3, If inner_state becomes a concrete type, then I don't know if this can be handled, and if so how? My best idea so far is for the inner_state to call process_event on the outer state machine and rewrite the outer machine's state transition table thus: inner_state + some_synthetic_event / do_some_stuff() == outer_s2, inner_state + other_synthetic_event / do_other_stuff() == outer_s3 The xxxx_synthetic_event's would be generated from within the inner state machine when it reaches one of the pseudo exit states. So in summary I would like to know: 1) Is there a documented example of putting a concrete wrapper around a inner state machine. 2) What is the list of limitations of doing this. e.g. exit_pt_ not working. 3) How should I deal with transitions in the outer state machine that were making use of exit_pt_ P.S. I've got to say that I think MSM is great! thanks - - Mark

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Re: [Boost-users] [serialization] Please help me solve this compile error.
by Brian Wood 30 Jul '14

30 Jul '14

Bjorn Reese writes: On 07/30/2014 04:01 AM, Paul Blampspied wrote: >> boost::archive::binary_ oarchive oa(file); >> oa << PersistentManagedArray<int>(size, capacity, ints); //This line does not compile ! > > The stream operator in Boost.Serialization does not take temporary > objects, so create the PersistentManagedArray<T> object on a separate > line, and then pass it to the stream. The C++ Middleware Writer <http://webEbenezer.net> supports temporary objects. Here's an example: front_messages_middle::Marshal(sendbuf, cmw::marshalling_integer(::strtol(argv[1],0,10))); It doesn't support PersistentManagedArray, but I'm willing to consider adding support for that. More info here - http://webEbenezer.net/about.html -- Brian Ebenezer Enterprises http://webEbenezer.net

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[MSM] how to use a compilation firewall around inner state machines
by Mark Bartosik 30 Jul '14

30 Jul '14

I have a state machine implemented with MSM (eUML) that currently has 80 transitions, there are two inner state machines. Compilation time is not great, but I have been dealing with it by BOOST_MSM_FAVOR_COMPILE_TIME and using parallel compilation where possible. Slow compilation time is an irritation and productivity killer, but my larger worry is that eventually the compiler will run out of memory. Especially as I will likely have to add another inner state machine with about 40 more transitions. Current we are using VS2008 but planning on moving everyone in the team to the VS2012 toolset but running under the VS2013 environment. I don't know if this will help, I doubt it. Currently compilation memory usage is up to 2.5GB per translation unit. So I would like to use a compilation firewall around the inner state machines. My plan is to implement concrete types for the inner state machines, with a process_event function: boost::msm::back::HandledEnum process_event( const boost::any & event ); Then within this function test for each event type to be handled by the inner state machine, and forward to a regular MSM state machine contained within the inner concrete type. I am hoping that this, plus on_entry and on_exit functions is about all I need to do. I expect that I will be able to get this to work, although an example on how to put a concrete wrapper around an inner state machine would be great, and importantly a list of limitations and work arounds for this technique would be helpful. My problem is that the outer state machine transition table has rows like this: exit_pt_( inner_state, inner_state_some_pseudo_exit_state ) / do_some_stuff() == outer_s2, exit_pt_( inner_state, inner_state_other_pseudo_exit_state ) / do_other_stuff() == outer_s3, If inner_state becomes a concrete type, then I don't know if this can be handled, and if so how? My best idea so far is for the inner_state to call process_event on the outer state machine and rewrite the outer machine's state transition table thus: inner_state + some_synthetic_event / do_some_stuff() == outer_s2, inner_state + other_synthetic_event / do_other_stuff() == outer_s3 The xxxx_synthetic_event's would be generated from within the inner state machine when it reaches one of the pseudo exit states. So in summary I would like to know: 1) Is there a documented example of putting a concrete wrapper around a inner state machine. 2) What is the list of limitations of doing this. e.g. exit_pt_ not working. 3) How should I deal with transitions in the outer state machine that were making use of exit_pt_ P.S. I've got to say that I think MSM is great! thanks - - Mark

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equivalent of java.util.properties
by David Frank 30 Jul '14

30 Jul '14

I'm wondering if there is a boost equivalent of the java.util.properties package which can read java properties file. Thanks, Dave.

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revisiting casting a boost::shared_ptr to void*
by Chris Cleeland 30 Jul '14

30 Jul '14

I'm resurrecting this topic: https://groups.google.com/forum/#!searchin/boost-list/shared_ptr$20void*/bo… because there is an unaddressed issue in it that I'm about to run into: "... beware the pointee may be deleted if the last copy of the shared pointer goes out of scope, as the raw pointer won't have incremented the reference count." I cannot be the first person to run into this--a common issue when crossing an API boundary. Has anyone come up with a good, safe solution wherein the reference count gets properly incremented? -- Chris Cleeland

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[Graph] Large Graphs: performace boost
by Sensei 30 Jul '14

30 Jul '14

Dear all, Facing an increasing size in my experiments, I am wondering now if my data structure is still valid. I need to traverse a graph (with my custom A*) that now can easily contain 10M-100M nodes and 100M-400M edges. The graph is (now) without weights, but this may change in the future. The only thing that is guaranteed not to change is that the graph is immutable. The graphs might even be larger, and at some point I will move to parallel BGL, but not now. To spare some memory, I am using a CSR graph: typedef boost::compressed_sparse_row_graph<boost::bidirectionalS> boost_graph; graph_ = new boost_graph(boost::edges_are_unsorted_multi_pass, results.begin(), results.end(), nodelist().size()); I am dubious if this the best solution. I have two objectives right now, optimize with respect to 1) memory consumption, and 2) graph traversal time. The main operation I need to do on graph is just "given a node, find the adjacent ones" (with my A*). Do you suggest to switch to another graph data structure? How do you think I will sacrifice time for memory, and vice versa, if I move for instance to an adjacency list? Thanks for any suggestion!

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Boost Based Proxy
by asim 29 Jul '14

29 Jul '14

In SSl case proxy will become a tunnel so whatever encrypted data i will get from client i have to forward it to server.But i am unable to read content as connection is keep alive (means no end of file exception) and due to encryption no header based reading i can do then how to read it. -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Based-Proxy-tp4665704.html Sent from the Boost - Users mailing list archive at Nabble.com.

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[Serialization] XML: Necessity of attribute class_id although class_name is given
by Frank Stähr 29 Jul '14

29 Jul '14

Hello everybody, I would like to know what the purpose of the xml attribute class_id is, how it works and in which cases it can be omitted. An example: “Base” is the (abstract) base class of _GMTF_ and _TTF_, and _Hist_ also has got a similar base class. If a pointer of Hist is a member of GMTF and you want to serialize a pointer of Base, you get something like: <filter class_id="0" class_name="GMTF"> <m_bufHalfMaxSize>4</m_bufHalfMaxSize> <m_cutDetector class_id="1" class_name="Hist"></m_cutDetector> </filter> Here, the macros • BOOST_CLASS_EXPORT_GUID(...), • BOOST_CLASS_IMPLEMENTATION(..., boost::serialization::object_serializable) and • BOOST_CLASS_TRACKING(..., boost::serialization::track_never) are used. The problem now is: Although the exact classes are given by human-readable class names (and used!), you cannot omit or change the class_id. If you edit the XML file by hand, it can become invalid (-> exception on reading). It seems that the class ids are just ascending non-negative numbers. What are the rules for choosing the class ids? Why are they necessary? Is there a trick to remove this attribute or at least to ignore it? Thanks, Frank -- Frank Stähr Technische Universität Berlin Communication Systems Group Sekr. EN1 Einsteinufer 17 10587 Berlin, Germany

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Pipe and Filters pattern with boost?
by Journeyer J. Joh 29 Jul '14

29 Jul '14

Hello list! I'd like to find a good approach to implement the Pipe and Filters pattern with boost. Could someone recommend me some useful boost library for this purpose? I only know asio. Is there any known example source code for this - Pipe and Filters pattern with boost. Thank you very much in advance! ---------------------------------------- Journeyer J. Joh o o s a p r o g r a m m e r a t g m a i l d o t c o m ----------------------------------------

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[Boost 1.56 Beta] [Serialization] Compilation problem with classes having special new operators
by Hijok Payne 28 Jul '14

28 Jul '14

I was trying out the new Boost 1.56 beta and some of my serialization code fails to compile (they work fine with previous versions of Boost e.g. Boost 1.55). I am trying to do serialization of Eigen (http://eigen.tuxfamily.org/) matrices with following code: #include <Eigen/Core> #include <fstream> #include <boost/serialization/vector.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> //Boost Serialization of Eigen Matrix namespace boost { template<class Archive, typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols> inline void serialize(Archive & ar, Eigen::Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>& t, const unsigned int file_version) { size_t rows = t.rows(), cols = t.cols(); ar & rows; ar & cols; if (rows * cols != t.size()) t.resize(rows, cols); ar & boost::serialization::make_array(t.data(), t.size()); } } //Simple helper for serialization to a file template <typename T> bool serialize(const T& data, const std::string& filename) { std::ofstream ofs(filename.c_str(), std::ios::out | std::ios::binary); if (!ofs.is_open()) return false; { // use scope to ensure archive goes out of scope before stream boost::archive::binary_oarchive oa(ofs); oa << data; } ofs.close(); return true; } //Simple helper for de-serialization from a file template <typename T> bool deSerialize(T& data, const std::string& filename) { std::ifstream ifs(filename.c_str(), std::ios::in | std::ios::binary); if (!ifs.is_open()) return false; { // use scope to ensure archive goes out of scope before stream boost::archive::binary_iarchive ia(ifs); ia >> data; } ifs.close(); return true; } int main(int argc, char *argv[]) { typedef Eigen::Vector3d VectorType; VectorType* vec = new VectorType(1, 2, 3); serialize(vec, "v4d.dat"); std::cout << "v4d =\n" << *vec << std::endl; VectorType* vec_in; deSerialize(vec_in, "v4d.dat"); std::cout << "v4d_in =\n" << *vec_in << std::endl; return 0; } The error in Visual studio 2013 says: boost/archive/detail/iserializer.hpp(237): error C2665: 'Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete' : none of the 3 overloads could convert all the argument types 2> c:\users\abhijit\codes\installs\eigen\eigen-install\include\eigen3\eigen\src/Core/PlainObjectBase.h(132): could be 'void Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete(void *,const std::nothrow_t &) throw()' 2> c:\users\abhijit\codes\installs\eigen\eigen-install\include\eigen3\eigen\src/Core/PlainObjectBase.h(132): or 'void Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete(void *,void *) throw()' 2> while trying to match the argument list '(VectorType *, size_t)' 2> C:\Boost\boost-1_56_0_b1\boost/archive/detail/iserializer.hpp(224) : while compiling class template member function 'void boost::archive::detail::heap_allocation<T>::has_new_operator::invoke_delete(T *)' There is also the following note, but I cannot seem to understand this. // if compilation fails here, the likely cause that the class // T has a class specific new operator but no class specific // delete operator which matches the following signature. Fix // your program to have this. Note that adding operator delete // with only one parameter doesn't seem correct to me since // the standard(3.7.4.2) says " // "If a class T has a member deallocation function named // 'operator delete' with exactly one parameter, then that function // is a usual (non-placement) deallocation function" which I take // to mean that it will call the destructor of type T which we don't // want to do here. I want to understand this issue because this breaks a lot of existing code.

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Geometry: modifiable?
by Jeremy Murphy 28 Jul '14

28 Jul '14

Is there a generic way to modify geometry structurally? Say if I have a ring and I want to insert a new point? Or would I need to reach into the underlying container to make that kind of change? Thanks, cheers. Jeremy

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[SmartPtr] enable_shared_from_raw
by Gavin Lambert 27 Jul '14

27 Jul '14

Hi all, Firstly, any chance this could get some documentation? Is the author still around? I'm thinking about using this at the moment for two separate reasons (and ways in which enable_shared_from_this seems to fall short): 1. shared_from_this can't be used from the constructor (requiring factory-method-init shenanigans); reportedly (https://groups.google.com/forum/#!topic/boost-list/8JWFZ56ry6k) shared_from_raw can, although I can't find specific details on the caveats mentioned. 2. What I *really* want to be able to do is to create a child object (most commonly a callback functor) that contains a weak_ptr, and it seems silly (and badly performant) to use the usual factory-init pattern to call shared_from_this just to degrade it back to a weak_ptr. And it should be possible to obtain that weak_ptr before any shared_ptr exists, and "fix" it later to point at the real shared_ptr, especially if it is known that the weak_ptr will never actually be used until that real shared_ptr exists. enable_shared_from_raw almost seems to fit the bill (according to http://stackoverflow.com/questions/22184772/why-is-boostenable-shared-from-…) but I encountered the same problem as in this post (http://lists.boost.org/boost-users/2013/05/78833.php) it works with shared_from_raw but not weak_from_raw. However this change: https://github.com/boostorg/smart_ptr/pull/8 fixes that. It looks like the two calls went down different code paths for some reason I can't fathom. Making this change (or the similar-but-better-style one mentioned in the PR discussion) makes the above scenario work as expected. I'm not sure if there was some specific reason to not do this before or if it was just an oversight. Any chance this can make it into 1.56? Or is it too late for that? Regards, Gavin Lambert

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[mpi] potentially blocking send - require blocking
by Dave Clarke 25 Jul '14

25 Jul '14

The boost::mpi documentation for send() is: "This routine executes a potentially blocking send" This differs from MPI_Send() "This routine will block until the message is sent to the destination." I am developing an application which requires the code not to progress until the communication is complete. In which situations does "potentially blocking" apply? And, is there a way of guaranteeing it is complete, the equivalent of MPI_Wait() for MPI_Isend()? Regards, Dave

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Compiling boost on Windows
by Freddy Martinez Garcia 24 Jul '14

24 Jul '14

Hi guys… I need compile the boost for windows but I’m not a windows user… I had made some compilation but the files generated by gcc (from MinGW) has .a extension and not .lib or .dll extension… how can I change that ?? best regard Freddy Martinez Garcia Lic. Ciencia de la Computacion C++ and Qt Senior Developer freddy311082(a)gmail.com

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unsubscribe
by Richard Greene 23 Jul '14

23 Jul '14

1 0

[mpl] BOOST_MPL_ASSERT_MSG for static_assert
by Michael Powell 23 Jul '14

23 Jul '14

Hello, I would like to add some diagnostic messages during compile time, potentially enumerating one or more types as well. static_assert is great for simple messages but falls a bit short due to inability to list types and such. I wonder if BOOST_MPL_ASSERT_MSG is the right answer, however, I am getting the following errors: BOOST_MPL_ASSERT_MSG( std::is_base_of<xnode, Node>::value , "requested type is not a node" , (types<node_type>) ); 1>i:\source\kingdom software\cppxml\xml\domain\parts\xnode.h(111): warning C4002: too many actual parameters for macro 'BOOST_MPL_ASSERT_MSG' It's an error message, but not the one(s) I am expecting. Do I need to enable something, preprocessor definition, something like that? Best regards, Michael Powell

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libboost_thread.a Cross-compile Linaro (ARM-Linux)
by Joseph Longhi 23 Jul '14

23 Jul '14

Hi, I have been trying to get a static library for boost_thread to be built but have so far been unable to. When running: ./b2 toolset=gcc-arm target-os=linux --with-threads The results show 2 skipped which are libboost_thread.a and libboost_system.a. I have all the shared objects built but can't seem to get around this problem. Any help would be greatly appreciated.

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Re: [Boost-users] [odeint] optional data
by Erik Schultheis 22 Jul '14

22 Jul '14

Thanks for the fast response. > > Hi > > On 07/22/2014 01:24 AM, Erik Schultheis wrote: > > Dear all, > > > > i am simulating particle trajectories, and depending on the data i want > > to generate i may or may not have to track additional data [boost.ublas > > c_matrix] along those trajectories. Right now i enable/disable that via > > a template parameter (so, using std::tuple(vec, vec) or tuple(vec, vec, > > c_matrix) and fusion_algebra), which has a few drawbacks. > > The algorithm is already templated to support varying dimensions via a > > template parameter, so the additional data practically doubles the > > number of template instantiations for system and all possible observers. > > This actually got so bad that gcc (mingw gcc 4.8) refuses to compile > > with debugging enabled. Therefore, i would like to make the switch > > between tracking the matrix and ignoring it a runtime choice instead of > > a template parameter. > > I don't understand fully what you exactly want to do. Can you show us > some more code? Can you put the tracking into an observer? I mean, do > you need to solve an ODE to track the additional data? > Unfortunatly, the tracking is an ode itself, so the change depends on the position and the current matrix value, so it cannot be done inside of an observer. As for the current implementation: I have a class BasicTracer<S, I>, where S is the template parameter that decides the state type (currently one of std::array<vec<2>, 2>, std::array<vec<3>, 2>, std::tuple<vec<2>, <vec<2>, matrix<4>> and std::tuple<vec<3>, vec<3>, matrix<6>>) and I the integration startegy (either Integrator, that only operates on the vectors, or MonodromyIntegrator, that also operates on the matrix). The reason for this is that I have two different use cases for the program: 1) a human-viewable visualisation of the trajectories that does not need matrices, and 2) the actual data i want to generate. Since 1) needs far more trajectories to be calculated, it is really helpful that the computation time in this case is lower. With the mentioned limitation (gcc refuses to compile with -g, "tracer.o: too many sections (50892)" and "ccQF7l7o.s: Fatal error: can't close .obj\Debug\src\tracer.o: File too big") the code works as it is now. For now i have only worked with small problem sizes, where the wait time for a result is in the order of a few minutes, however, this is going to change and therefore i want to parallelize the code. The differentiation between he use cases via templates make the code quite complex at times, and i hope to reduce that complexity before i add the parallelization. Therefore, I want to transform from a templated approach to a runtime approach. I am not sure if it is possible to make the code select the dimension at runtime without significant performance impact, but at least the second parameter should be removable without increasing runtime significantly. I am not really sure which parts of the code to post to significantly inprove my description. The tracer itself is a type like template class BasicTracer<std::tuple<vec<3>, vec<3>, monodromy_matrix<3>>, MonodromyIntegrator<std::tuple<vec<3>, vec<3>, monodromy_matrix<3>>>>; or template class BasicTracer<std::array<vec<2>, 2>, Integrator<std::array<vec<2>, 2>>>; the integration is performed like double starte = mEnergy(p); try { mMasterObserver.startTrajectory(p); perform_integration(mIntegrator, p, 2.0, 1.0 / mPotential.getSize(), mMasterObserver, mAbsErrorBound, mRelErrorBound); } catch(int& i) {}; /// \todo this is the only reason for getLastState's existence mEnergyError += std::pow( starte - mEnergy( mMasterObserver.getLastState() ), 2 ); where perform integration just sets parameters to the odeint function: template<typename System, typename State, typename Observer> std::size_t perform_integration(const System& system, State& start, double t_end, double dt, Observer& obs, double abs_err, double rel_err) { using namespace boost::numeric::odeint; // when range access is possible, try range algebra, otherwise, try fusion using algebra_type = typename std::conditional<boost::has_range_iterator<State>::value, range_algebra, fusion_algebra>::type; typedef runge_kutta_cash_karp54<State, double, State, double, algebra_type> error_stepper_type; typedef controlled_runge_kutta<error_stepper_type> controlled_stepper_type; typedef default_error_checker<typename controlled_stepper_type::value_type, typename controlled_stepper_type::algebra_type> error_checker_type; controlled_stepper_type stepper(error_checker_type(abs_err, rel_err)); return integrate_const(stepper, system, start, 0.0, t_end, dt, std::ref(obs) ); } and the operator() of the integrators look like template<class S> void Integrator<S>::operator()( const S& state, S& deriv, double/*t*/ ) const { using namespace system_state; auto position = get_position(state); auto p = position * mPotential.getSize(); double x = p[0]; double y = p[1]; // prevent out of bounds access if(y < 0 || y > mPotential.getSize()-1 || x < 0 || x > mPotential.getSize()-1) { throw(1); }; // calculate acceleration auto& acceleration = get_velocity(deriv); for(int i = 0; i < DIMENSION; ++i) { /// the compiler should be able to ompimize this std::array<int, DIMENSION> didx; didx.fill(0); didx[i] = 1; acceleration[i] = -linearInterpolate( mPotential.getDerivative(didx), p ); } // change in position = current velocity get_position( deriv ) = get_velocity( state ); } template<class S> void MonodromyIntegrator<S>::operator()( const S& state, S& deriv, double/*t*/ ) const { using namespace system_state; auto position = get_position(state); auto p = position * mPotential.getSize(); double x = p[0]; double y = p[1]; // prevent out of bounds access if(y < 0 || y > mPotential.getSize()-1 || x < 0 || x > mPotential.getSize()-1) { throw(1); }; // calculate acceleration auto& acceleration = get_velocity(deriv); for(int i = 0; i < DIMENSION; ++i) { std::array<int, DIMENSION> didx; didx.fill(0); didx[i] = 1; acceleration[i] = -linearInterpolate( mPotential.getDerivative(didx), p ); } // change in position = current velocity get_position( deriv ) = get_velocity( state ); // change in monodromy boost::numeric::ublas::axpy_prod(getMonodromyCoeff( mPotential, p ), get_data(state), get_data(deriv), true); } If there is some other part of the code that would be helpful, please let me know. > > However, the cost of tracking that matrix is quite high (that is why it > > is optional), but simply disableing the d matrix / dt calculation in the > > system does not speed up the calculation much (86 s -> 58 s vs 27 s > > without matrix). A lot of time is spent in adding and multiplying > > numbers that are not used anywhere, or actually even copying them (e.g > > std::swap(c_matrix, c_matrix) shows up quite high in gprof (even though > > i am not sure how reliable the -pg option is in conjunction with -O3)). > > > > So what i am asking here is for suggestions how to best let odeint treat > > the c_matrix as uninitialized memory and never perform any operations on > > that depending on a runtime parameter. > > Options i thought of were: > > * deriving a class from c_matrix and providing my own versions of > > operator overloads that check a flag: > > as far as i know, boost.ublas matrices use some template magic to > > let operators only return expression templates to optimize evaluation if > > operations are chained, and i would not be sure about how to actually > > retain that behaviour in case the matrix is tracked. > > * creating my own algebra class: > > from what i could tell from a few quick glances into the algebra > > files, this would probably be conceptually easier than the other option, > > but would require a lot of repetetive coding. > > > > Does anyone have suggestion for a more efficient implementation strategy? > > Have you considered to use a fusion view which only points to tuple( vec > , vec ). This could be used as the state type you use. Nevertheless, you > need to instantiate the stepper with a real resizable state_type which > you could be again a tuple( vec , vec ). > No, I didn't know about fusion view up until now :), so i am going to take a look at it. Why would I need a resizable state_type? Whether I track the matrix or not is decided before the call into the integrate function. > > >From the options you showed here, an own algebra looks most promising. > This algebra you also be implemented in terms of the existing > fusion_algebra and redirect all calls to fusion_algebra.

2 1

[Statechart] How to decide between post_event and process_event atrun time ?
by Philippe DAVID 22 Jul '14

22 Jul '14

Hi, I have a method in which I want to post/process an event. The thing is, this method can be called from outside the state machine (so I need to call process_event), or indirectly by a reaction of the state machine (in this case I must call post_event since process_event is not reentrant). I don't want to write 2 distinct methods to do this (one that calls post, and the other process), I would much rather prefer adding a 'if' in my method that tells me if I have to call process_event or post_event (if I'm being called indirectly by the state machine or not). Is there a way to do this with statechart ? regards, Philippe

3 3

[ptr container] up to date?
by Michael Powell 22 Jul '14

22 Jul '14

Hello, I am considering putting Boost Pointer Container to use in an application to help with, among other things, the polymorphic slicing issue. I've got a domain model which potentially has exactly that creeping in, vector of shared_ptr to base class, with heterogeneous vector composition. http://www.boost.org/doc/libs/1_55_0/libs/ptr_container/doc/ptr_container.h… I was reading a lot of references to std::auto_ptr, which is a deprecated feature these days (http://www.cplusplus.com/reference/memory/auto_ptr/) Also the last update was in 2007 or thereabouts. Is this up to date with current language features such as std's?, i.e. std::unique_ptr, std::shared_ptr? Just generally, this is a fitness for use query. Thank you... Best regards, Michael Powell

2 1

[1.56.0] Beta 1 Available
by Marshall Clow 22 Jul '14

22 Jul '14

Boost release 1.56.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/boost/1.56.0.beta.1/ This release contains 2 new libraries: * Align: Memory alignment functions, allocators, and adaptors, from Glen Fernandes. * Type_Index: Runtime/Compile time copyable type info, from Antony Polukhin. Modularization Boost version control has migrated to a system using git submodules. This shouldn't make too much of a difference to users, although the directory structure is now a bit different. Parts of some libraries have been moved into different modules, and several new modules have been extracted from existing code. All header paths should remain the same. The new modules are: * Assert: Customizable assert macros. Maintained by Peter Dimov. * Core: Core utilities used by other libraries, with minimal dependencies. Maintained by Peter Dimov, Glen Fernandes and Andrey Semashev. * Lexical_Cast: General literal text conversions, such as an int represented a string, or vice-versa, from Kevlin Henney. * Throw_Exception: A common infrastructure for throwing exceptions from Boost libraries, from Emil Dotchevski. * Winapi: Windows API declarations without <windows.h>, for internal Boost use. For details of what's in the release, see http://www.boost.org/users/history/version_1_56_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

9 12

Building modular-boost on windows with masm32?
by Alle Meije Wink 22 Jul '14

22 Jul '14

Dear all, I have tried to build modular-boost on windows (win7 64bit) using the mingw toolset. The steps that I followed (after some trial & error) are: 1. clone boost-modular from into %home%\usr\local\boost 2. in that boost directory; type bootstrap mingw ===========output=============== Building Boost.Build engine Bootstrapping is done. To build, run: .\b2 To adjust configuration, edit 'project-config.jam'. Further information: - Command line help: .\b2 --help - Getting started guide: http://boost.org/more/getting_started/windows.html - Boost.Build documentation: http://www.boost.org/boost-build2/doc/html/index.html ================================ 3. after apparently successful bootstrap, type b2 -a -d+2 -q --prefix=c:\users\amwink\usr\local --build-type=complete --build-dir=build toolset=gcc link=shared runtime-link=shared The output is below. So the commands cl.exe and ml.exe, which are not in mingw but can be used from the masm32 package are found, but their output is not recognised (as I understand) Is that correct? Would there be a way around this other than installing VC++? Many thanks Alle Meije ===========output=============== Building the Boost C++ Libraries. Performing configuration checks - symlinks supported : yes (cached) - 32-bit : yes (cached) - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - has_icu builds : no (cached) warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : no (cached) - iconv (libc) : no (cached) - iconv (separate) : yes (cached) - icu : no (cached) - icu (lib64) : no (cached) - g++ -shared-* supported : no (cached) - message-compiler : no (cached) - compiler-supports-ssse3 : yes (cached) - compiler-supports-avx2 : yes (cached) - gcc visibility : yes (cached) - long double support : yes (cached) warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. warning: No python installation configured and autoconfiguration note: failed. See http://www.boost.org/libs/python/doc/building.html note: for configuration instructions or pass --without-python to note: suppress this message and silently skip all Boost.Python targets - zlib : no (cached) - zlib : no (cached) warning: Skipping Boost.Locale library with threading=single. warning: Skipping Boost.Thread library with threading=single. warning: Skipping Boost.Wave library with threading=single. - zlib : no (cached) Component configuration: - atomic : building - chrono : building - container : building - context : building - coroutine : building - date_time : building - exception : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - locale : building - log : building - math : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - sync : building - system : building - test : building - thread : building - timer : building - wave : building gcc.compile.c++ build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\lockpool.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -mthreads -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_DYN_LINK=1 -DBOOST_ATOMIC_SOURCE -DBOOST_USE_WINDOWS_H -DNDEBUG -D_WIN32_WINNT=0x0500 -I"." -c -o "build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\lockpool.o" "libs\atomic\src\lockpool.cpp" gcc.link.dll build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll.a "g++" "-Wl,--out-implib,build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll.a" -o "build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll" -shared -Wl,--start-group "build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\lockpool.o" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -mthreads -lkernel32 common.copy stage\lib\libboost_atomic-mgw48-mt-1_56.dll.a copy /b "build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll.a" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_atomic-mgw48-mt-1_56.dll.a" build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll.a 1 file(s) copied. common.copy stage\lib\libboost_atomic-mgw48-mt-1_56.dll copy /b "build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_atomic-mgw48-mt-1_56.dll" build\boost\bin.v2\libs\atomic\build\gcc-mingw-4.8.1\release\threading-multi\libboost_atomic-mgw48-mt-1_56.dll 1 file(s) copied. gcc.compile.c++ build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\error_code.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -mthreads -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DNDEBUG -I"." -c -o "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\error_code.o" "libs\system\src\error_code.cpp" gcc.link.dll build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll.a "g++" "-Wl,--out-implib,build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll.a" -o "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll" -shared -Wl,--start-group "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\error_code.o" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -mthreads common.copy stage\lib\libboost_system-mgw48-mt-1_56.dll.a copy /b "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll.a" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_system-mgw48-mt-1_56.dll.a" build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll.a 1 file(s) copied. common.copy stage\lib\libboost_system-mgw48-mt-1_56.dll copy /b "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_system-mgw48-mt-1_56.dll" build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll 1 file(s) copied. gcc.compile.c++ build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\chrono.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -mthreads -Wextra -Wno-long-long -Wno-variadic-macros -pedantic -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRE CATED -DNDEBUG -I"." -c -o "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\chrono.o" "lib s\chrono\src\chrono.cpp" gcc.compile.c++ build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\thread_clock.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -mthreads -Wextra -Wno-long-long -Wno -variadic-macros -pedantic -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DNDEBUG -I"." -c -o "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\thread_clock.o " "libs\chrono\src\thread_clock.cpp" gcc.compile.c++ build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\process_cpu_clocks.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -mthreads -Wextra -Wno-long-long -Wno-variadic-macros -pedantic -DBOOST_ALL_DYN_LINK=1 -DBOOST_ALL_NO_LIB=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRE CATED -DNDEBUG -I"." -c -o "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\process_cpu_clocks.o" "libs\chrono\src\process_cpu_clocks.cpp" gcc.link.dll build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll.a "g++" "-Wl,--out-implib,build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll.a" -o "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll" -shared -Wl,--start-group "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-m ulti\chrono.o" "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\thread_clock.o" "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\process_cpu_clocks.o" "build\boost\bin.v2\libs\system\build\gcc-mingw-4.8.1\release\threading-multi\libboost_system-mgw48-mt-1_56.dll.a" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -mthreads common.copy stage\lib\libboost_chrono-mgw48-mt-1_56.dll.a copy /b "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll.a" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_chrono-mgw48-mt-1_56.dll.a" build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll.a 1 file(s) copied. common.copy stage\lib\libboost_chrono-mgw48-mt-1_56.dll copy /b "build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_chrono-mgw48-mt-1_56.dll" build\boost\bin.v2\libs\chrono\build\gcc-mingw-4.8.1\release\threading-multi\libboost_chrono-mgw48-mt-1_56.dll 1 file(s) copied. gcc.compile.c build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\alloc_lib.o "g++" -x c -O3 -finline-functions -Wno-inline -Wall -mthreads -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTAINER_DYN_LINK=1 -DN DEBUG -I"." -c -o "build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\alloc_lib.o" "libs\container\src\alloc_lib.c" gcc.link.dll build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll.a "g++" "-Wl,--out-implib,build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll.a" -o "build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll" -shared -Wl,--start-group "build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\alloc_lib.o" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -mthreads common.copy stage\lib\libboost_container-mgw48-mt-1_56.dll.a copy /b "build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll.a" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_container-mgw48-mt-1_56.dll.a" build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll.a 1 file(s) copied. common.copy stage\lib\libboost_container-mgw48-mt-1_56.dll copy /b "build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll" + this-file-does-not-exist-A698EE7806899E69 "stage\lib\libboost_container-mgw48-mt-1_56.dll" build\boost\bin.v2\libs\container\build\gcc-mingw-4.8.1\release\threading-multi\libboost_container-mgw48-mt-1_56.dll 1 file(s) copied. Jamfile<C:\Users\amwink\usr\local\boost\libs\context\build>.masm build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\make_i386_ms_pe_masm.o ml /c /Fo"build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\make_i386_ms_pe_masm.o" "libs\context\src\asm\make_i386_ms_pe_masm.asm" Microsoft (R) Macro Assembler Version 6.14.8444 Copyright (C) Microsoft Corp 1981-1997. All rights reserved. Assembling: libs\context\src\asm\make_i386_ms_pe_masm.asm Jamfile<C:\Users\amwink\usr\local\boost\libs\context\build>.masm build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\jump_i386_ms_pe_masm.o ml /c /Fo"build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\jump_i386_ms_pe_masm.o" "libs\context\src\asm\jump_i386_ms_pe_masm.asm" Microsoft (R) Macro Assembler Version 6.14.8444 Copyright (C) Microsoft Corp 1981-1997. All rights reserved. Assembling: libs\context\src\asm\jump_i386_ms_pe_masm.asm gcc.compile.c++ build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\threading-multi\dummy.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -mthreads -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_CONTEXT_SOURCE -DNDEBUG -I"." -c -o "build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\ threading-multi\dummy.o" "libs\context\src\dummy.cpp" gcc.link.dll build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\threading-multi\libboost_context-mgw48-mt-1_56.dll.a "g++" "-Wl,--out-implib,build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\threading-multi\libboost_context-mgw48-mt-1_56.dll.a" -o "build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\threading-multi\libboost_context-mgw48-mt-1_56.dll" -shared -Wl,--start-group "build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\make_i386_ms_pe_masm.o" "build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\jump_i386_ms_pe_masm.o" "build\boost\bin.v2\libs\co ntext\build\gcc-mingw-4.8.1\release\threading-multi\dummy.o" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -mthreads build\boost\bin.v2\libs\context\build\gcc-mingw-4.8.1\release\address-model-32\architecture-x86\threading-multi\asm\make_i386_ms_pe_masm.o: file not recognized: File format not recognized collect2.exe: error: ld returned 1 exit status ...skipped <pstage\lib>libboost_context-mgw48-mt-1_56.dll.a for lack of <pbuild\boost\bin.v2\libs\context\build\gcc-ming w-4.8.1\release\threading-multi>libboost_context-mgw48-mt-1_56.dll.a... ...failed updating 1 target... ================================

4 8

[odeint] optional data
by Erik Schultheis 22 Jul '14

22 Jul '14

Dear all, i am simulating particle trajectories, and depending on the data i want to generate i may or may not have to track additional data [boost.ublas c_matrix] along those trajectories. Right now i enable/disable that via a template parameter (so, using std::tuple(vec, vec) or tuple(vec, vec, c_matrix) and fusion_algebra), which has a few drawbacks. The algorithm is already templated to support varying dimensions via a template parameter, so the additional data practically doubles the number of template instantiations for system and all possible observers. This actually got so bad that gcc (mingw gcc 4.8) refuses to compile with debugging enabled. Therefore, i would like to make the switch between tracking the matrix and ignoring it a runtime choice instead of a template parameter. However, the cost of tracking that matrix is quite high (that is why it is optional), but simply disableing the d matrix / dt calculation in the system does not speed up the calculation much (86 s -> 58 s vs 27 s without matrix). A lot of time is spent in adding and multiplying numbers that are not used anywhere, or actually even copying them (e.g std::swap(c_matrix, c_matrix) shows up quite high in gprof (even though i am not sure how reliable the -pg option is in conjunction with -O3)). So what i am asking here is for suggestions how to best let odeint treat the c_matrix as uninitialized memory and never perform any operations on that depending on a runtime parameter. Options i thought of were: * deriving a class from c_matrix and providing my own versions of operator overloads that check a flag: as far as i know, boost.ublas matrices use some template magic to let operators only return expression templates to optimize evaluation if operations are chained, and i would not be sure about how to actually retain that behaviour in case the matrix is tracked. * creating my own algebra class: from what i could tell from a few quick glances into the algebra files, this would probably be conceptually easier than the other option, but would require a lot of repetetive coding. Does anyone have suggestion for a more efficient implementation strategy? Greetings Erik

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[type traits] redefine a type trait
by Michael Powell 21 Jul '14

21 Jul '14

Hello, Question: is there a way to delete or remove a type trait once it has been defined? And/or redefine it? Consider, I've got a default type trait, something like this. template<typename T> struct throws_exceptions { static const bool value = true; }; struct my_object { //does some work with or without exception }; template<> struct throws_exceptions<my_object> { static const bool value = false; } However, in my unit test code, I want to override the default behavior for test purposes. template<> struct throws_exceptions<my_object> { static const bool value = true; } Or just leave the type trait out. Actually, I'm not sure I just considered an answer to my own question. Possibly I need to separate the traits from the underlying things being modified, and leave it as an option whether to include the defaults, or define user-provided traits. Best regards, Michael Powell

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[msm] enque vs defer
by Raj Sambasivan 21 Jul '14

21 Jul '14

Hi boost-users/Christophe, Does enqueue and defer use the same underlying queue, and when i defer can i validate my unit testcase to check on the queue size using get_message_queue_size(). I did a quick test on defer and checking the queue size and it didnt work may be there is something wrong in my test program but wanted to check if anyone tried this out. thank you -raj

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linking err using log
by David Frank 20 Jul '14

20 Jul '14

Has anyone seen this:? boost/log/attributes/attribute_value_impl.hpp:47: undefined reference to `boost::log::v2s_mt_posix::attribute::impl::operator delete(void*, unsigned long)' In function `boost::log::v2s_mt_posix::attributes::attribute_value_impl<boost::posix_time::ptime>::~attribute_value_impl()': Thanks, Dave

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Push-Relabel undirected graph
by Charles Maske 20 Jul '14

20 Jul '14

Hi there, I'm working in a cut-tree implementation of gomoryhu algorithm and I have to compute max-flow on the input graph. I read about efficiency of the push-relabel algorithm and I want to do some tests but I can't get this because all reverse edges have to capacity equals 0. Someone knows one way to workaround this restriction? Other max-flow algorithms in BGL (edmonds-karp and boykov-kolmogorov) don't have this restriction, what do them more fast than push-relabel implementation. Thanks

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Generate random graphs
by Mandy Nour 20 Jul '14

20 Jul '14

Hello all, I need to generate random undirected simple graphs using The Erdos-Rényi methods and to extract its adjacency matrix into an std::vector. -- View this message in context: http://boost.2283326.n4.nabble.com/Generate-random-graphs-tp4665336.html Sent from the Boost - Users mailing list archive at Nabble.com.

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[variant] forward declarations
by Michael Powell 18 Jul '14

18 Jul '14

Hello, I've got some structs in a AST of sorts which the main player in the mix is a node. In at least one of the use cases, one of the variant types must be forward declared at the time the node can be declared. Possibly one or two other similar use cases. Error 2 error C2139: 'xml::xelement' : an undefined class is not allowed as an argument to compiler intrinsic type trait '__is_nothrow_constructible' i:\installs\development\boost.org\1.55.0\boost_1_55_0\stage\include\boost\type_traits\has_nothrow_constructor.hpp 24 1 xml However, I am bumping into C2139, above. Is there any way for variant to work with forward declared structs (or classes, etc)? Or am I just asking too much from C++? I am building against Visual Studio 2013, Boost 1.55. Thank you... Best regards, Michael Powell

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boost::lockfree::queue not working with -fgnu-tm
by Philipp Schoppe 18 Jul '14

18 Jul '14

Hello, I try to benchmark different queue implementations. I have a test program which includes the boost lockfree queue and some custom implementations where one is using gcc's STM. In order to compile it, I need to add the -fgnu-tm flag. I am using an up-to-date arch linux system with gcc 4.9.0 and boost 1.55.0 When adding this flag, I get a compilation error. This is a small example that illustrates the problem: errtest.cpp: #include <boost/lockfree/queue.hpp> int main () { boost::lockfree::queue<int> lfqueue; lfqueue.push(234); return 0; } Compiling it using g++ -std=c++11 -lboost_system -g -O3 -Wall -Werror -Wswitch-enum -fgnu-tm errtest.cpp -o test leads to an error.

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[Log] Extract severity value
by Olivier Tournaire 17 Jul '14

17 Jul '14

Hi all, I am trying to extract severity level from a log record, but i seems that I am doing it the wrong way. Here is the code I use: void LogDockWidget::receiveLog(boost::log::record_view const& rec, const std::string& log) { logging::value_ref< logging::trivial::severity_level > level = logging::extract< logging::trivial::severity_level >("Severity", rec); // ... } Here level.get() always returns "info". All my logs are done with the BOOST_LOG_TRIVIAL(...) macro. The formatter whereas displays correctly the severity level. Here is how it is defined: void LogDockWidget::init_logging() { boost::shared_ptr< logging::core > core = logging::core::get(); typedef sinks::synchronous_sink< QTextEditFormattedSinkBackend > sink_t; boost::shared_ptr< sink_t > sink(new sink_t); // ... logging::add_file_log( keywords::file_name = logFilename, keywords::auto_flush = true, keywords::format = ( BUILD_LOG_FORMATTER() ) ); sink->set_formatter( BUILD_LOG_FORMATTER() ); core->add_sink(sink); // Add attributes that we will use logging::add_common_attributes(); core->add_global_attribute( "ThreadID", attrs::current_thread_id()); } #define BUILD_LOG_FORMATTER() \ expr::stream \ << "[" << expr::format_date_time< boost::posix_time::ptime >("TimeStamp", "%Y-%m-%d %H:%M:%S") << "] " \ << expr::attr<unsigned int>("LineID") << " " \ << ": <" << logging::trivial::severity << "> " \ << " [" << expr::attr<attrs::current_thread_id::value_type>("ThreadID") << "] " \ << expr::if_(expr::has_attr(scope_attribute)) \ [ \ expr::stream << "[" << scope_attribute << "] " \ ] \ << expr::message Could you please let me know what I am doing wrong? Regards, Olivier

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