January 2014 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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[Range, Phoenix] What am I missing...
by Robert Jones 25 Apr '17

25 Apr '17

Hi Folks Can anyone explain the output of this program... #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 f( int i ) { return i * 2; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::copy; using boost::phoenix::arg_names::_1; copy( counting_range( 1, 5 ) | reversed | transformed( f ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; copy( counting_range( 1, 5 ) | reversed | transformed( bind( f, _1 ) ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } Which is... 8 6 4 2 1768406272 1768406272 1768406272 1768406272 I'm using Gcc 4.6.2 & Boost 1.53 Thx All.

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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

5 6

Statechart serialization
by mbrodeur65 04 Mar '15

04 Mar '15

Hi, I'm looking for a solution to serialize boost::statechart objects. I'm aware that this feature is on the statechart library todo list but was wondering if there are any workaround to achieve this with the latest boost release (1.34) ? thanks for your help ! mbrodeur65 -- View this message in context: http://www.nabble.com/Statechart-serialization-tf4131326.html#a11749139 Sent from the Boost - Users mailing list archive at Nabble.com.

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[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.

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[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

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conflicting intmax_t definitions - Boost 1.53 and gcc 4.8 incompatibility?
by Nate Finch 09 Apr '14

09 Apr '14

I recently upgraded to Ubuntu Trusty Tehr, and now the C++ project I'm working on won't build. It looks like the stdlib and Boost aren't working nicely together for some reason. A bunch of typedefs are conflicting between the two, below is one of the errors, where intmax_t is getting defined in two places. I'm not sure what changed, but I now have gcc (Ubuntu/Linaro 4.8.2-14ubuntu2) 4.8.2 and boost Version: 1.53.0.0ubuntu2 Here's an example error message: /usr/include/inttypes.h:290:8: error: reference to ‘intmax_t’ is ambiguous extern intmax_t imaxabs (intmax_t __n) __THROW __attribute__ ((__const__)); ^ In file included from /usr/lib/gcc/x86_64-linux-gnu/4.8/include/stdint.h:9:0, from /usr/include/inttypes.h:27, from src/uint256.h:11, from src/key.h:12, from src/crypter.h:8, from src/keystore.h:8, from src/script.h:14, from src/script.cpp:11: /usr/include/stdint.h:134:19: note: candidates are: typedef long int intmax_t typedef long int intmax_t; ^ In file included from /usr/include/boost/math_fwd.hpp:12:0, from /usr/include/boost/math/common_factor_ct.hpp:13, from /usr/include/boost/variant/variant.hpp:44, from /usr/include/boost/variant.hpp:17, from src/script.h:12, from src/script.cpp:11: /usr/include/boost/cstdint.hpp:306:50: note: typedef boost::long_long_type boost::intmax_t typedef ::boost::long_long_type intmax_t; Any help would be much appreciated. I'm fine with downgrading something, I'm just not sure what to downgrade.... or if there's an actual fix, that's cool too. -- View this message in context: http://boost.2283326.n4.nabble.com/conflicting-intmax-t-definitions-Boost-1… Sent from the Boost - Users mailing list archive at Nabble.com.

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Problems calling make_reversed_graph in a call to dijkstra from version 1.48
by Berit Dangaard Brouer 08 Apr '14

08 Apr '14

Hi, First of all thank you for providign the boost BGL library. I use it extensively. I am having some problems with some code, that works just fine using boost version 1.46, but cannot compile using version 1.48 and higher. I have a Bidirectional Graph using bundled properties defined as: struct Port { Port(int index=-1, int type=-1, int port_code=0, string UN="NN", string name="NN", int service_id=-1 ): m_index(index), m_type(type), m_port_code( port_code), UNLOCODE(UN), m_name(name), m_service_id(service_id) {} int m_index; int m_type;//0 port, 1 port call int m_port_code; string UNLOCODE; string m_name; int m_service_id; }; struct Edge { Edge( int id=-1, int type=-1, double weight=0.0, double cost=0.0, double dual_cost=0.0, double util=0.0, double cap=0.0, double r_cap=0.0 ) : m_idx(id), m_type(type), m_weight(weight) , m_cost(cost), m_dual_cost(dual_cost), m_utilization(util), m_capacity(cap), m_res_cap(r_cap) {} unsigned int m_idx; int m_type;//0 is load edge, 1 is voyage edge, 2 forfeited edge (commodity link) double m_weight; //distance double m_cost; //cost - only on load/unload/transhipment edges double m_dual_cost; double m_utilization; double m_capacity; double m_res_cap; //residual capacity }; //Graph typedef adjacency_list< vecS , vecS , bidirectionalS, Port, Edge> mcf_graph; I am trying to make a call to dijkstra on a reversed graph as follows: (the reversed graph is also a filtered graph, but I do not think this is an issue: dijkstra_shortest_paths (make_reverse_graph(fg), before_p, predecessor_map ( &p[0] ).distance_map ( &d[0] ).weight_map ( get ( &Edge::m_weight, fg) ).vertex_index_map ( get ( vertex_index,fg ) ) ); which works fine in 1.46, but it seems in 1.48 I can no longer use make_reverse_graph(<mcf_graph&>) (returning a reverse graph) with the bundled properties from fg. and I get the error (compressed summary - full details attached) usr/include/boost/property_map/property_map.hpp:354:56: error: no match for 'operator[]' in '((const boost::bundle_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge>, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>, Edge, double>&)pa)[k]' /usr/include/boost/property_map/property_map.hpp:354:56: note: candidate is: In file included from /usr/include/boost/graph/adjacency_list.hpp:44:0, from /home/chrkr/git/lsndp/include/ipheuristic.h:36, from /home/chrkr/git/lsndp/src/ipheuristic.cpp:29: /usr/include/boost/graph/properties.hpp:399:15: note: T& boost::bundle_property_map<Graph, Descriptor, Bundle, T>::operator[](boost::bundle_property_map<Graph, Descriptor, Bundle, T>::key_type) const [with Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge>; Descriptor = boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>; Bundle = Edge; T = double; boost::bundle_property_map<Graph, Descriptor, Bundle, T>::reference = double&; boost::bundle_property_map<Graph, Descriptor, Bundle, T>::key_type = boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>] /usr/include/boost/graph/properties.hpp:399:15: note: no known conversion for argument 1 from 'const boost::detail::reverse_graph_edge_descriptor<boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int> >' to 'boost::bundle_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge>, boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>, Edge, double>::key_type {aka boost::detail::edge_desc_impl<boost::bidirectional_tag, long unsigned int>}' From various sources I understand that as of 1.48 reverse graph is no longer an image of the graph, but another object, where I need the actual property maps and the property maps of the reversed graph, but I did not get much wiser on how to call dijkstra with the reversed graph given these new description. I tried defining the reverse graph as a separate object reverse_graph<mcf_graph> r_fg=reverse_graph(fg); dijkstra_shortest_paths (r_fg), before_p, predecessor_map ( &p[0] ).distance_map ( &d[0] ).weight_map ( get ( &Edge::m_weight, r_fg) ).vertex_index_map ( get ( vertex_index, r_fg ) ) ); indicating that I am not getting the right properties for the reverse graph: equired from here /usr/include/boost/graph/properties.hpp:420:44: error: no type named 'vertex_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /usr/include/boost/graph/properties.hpp:421:42: error: no type named 'edge_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /usr/include/boost/graph/properties.hpp:425:7: error: no type named 'vertex_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /usr/include/boost/graph/properties.hpp:429:7: error: no type named 'vertex_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /usr/include/boost/graph/properties.hpp:432:70: error: no type named 'vertex_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /usr/include/boost/graph/properties.hpp:434:7: error: no type named 'vertex_bundled' in 'class boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >' /home/chrkr/git/lsndp/src/ipheuristic.cpp:939:132: error: no matching function for call to 'get(double Edge::*, boost::reverse_graph<boost::adjacency_list<boost::vecS, boost::vecS, boost::bidirectionalS, Port, Edge> >&)' /home/chrkr/git/lsndp/src/ipheuristic.cpp:939:132: note: candidates are: In file included from /usr/include/boost/graph/adjacency_list.hpp:36:0, from /home/chrkr/git/lsndp/include/ipheuristic.h:36, from /home/chrkr/git/lsndp/src/ipheuristic.cpp:29: /usr/include/boost/property_map/property_map.hpp:179:19: note: template<class T> const T& get(const T*, std::ptrdiff_t) /usr/include/boost/property_map/property_map.hpp:179:19: note: template argument deduction/substitution failed: /home/chrkr/git/lsndp/src/ipheuristic.cpp:939:132: note: mismatched types 'const T*' and 'double Edge::*' In file included from /usr/include/boost/graph/graphviz.hpp:25:0, from /home/chrkr/git/lsndp/include/data.h:19, from /home/chrkr/git/lsndp/include/ipheuristic.h:46, from /home/chrkr/git/lsndp/src/ipheuristic.cpp:29: /usr/include/boost/property_map/dynamic_property_map.hpp:322:1: note: template<class Key> std::string boost::get(const string&, const boost::dynamic_properties&, const Key&) /usr/include/boost/property_map/dynamic_property_map.hpp:322:1: note: template argument deduction/substitution failed: Is the problem the bundled properties from the original graph or ? -- Best Regards, Ph.D. Berit Dangaard Brouer Post Doc. DTU Management Engineering, Management Science Technical University of Denmark Department of Management Engineering Produktionstorvet, Bygning 426 2800 Kgs. Lyngby blof(a)dtu.dk <mailto:blof@man.dtu.dk> www.ms.man.dtu.dk <http://www.ms.man.dtu.dk> http://www.maersk.com/innovation/leadingthroughinnovation/enerplan/ Please read about the ENERPLAN project here <http://www.maersk.com/innovation/leadingthroughinnovation/enerplan/>

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[asio] resolver::cancel() problem
by Matthew Edwards 14 Mar '14

14 Mar '14

In my application (and a separate test program) it seems as though the cancel() function on the resolver does not work as intended. For async resolves, the cancel functionality should abort them immediately and pass an 'operation aborted' error code to the callback handler. In my tests, I will resolve an invalid domain (this causes the resolve to take a few seconds, to demonstrate the problem), sleep for 100ms, then call cancel on the resolver object. No cancelling actually occurs, and the callback is simply triggered after a few seconds with a "No host found" error code, not the expected operation aborted. Has anyone experienced this before, or know how I might be using the resolver incorrectly?

3 2

Where is BOOST_TEST - the universal testing tool
by Adi Shavit 21 Feb '14

21 Feb '14

Hi, I read here<http://boost.2283326.n4.nabble.com/test-BOOST-TEST-universal-testing-tool-t…>and here <http://lists.boost.org/Archives/boost/2013/09/206202.php>about BOOST_TEST - the universal testing tool. Where can I find it? Is it still not part of the library? Thanks, Adi

7 15

path of test-binary
by dib 19 Feb '14

19 Feb '14

Hi, how can I get the path where b2 placed the binaries of boost tests? Problem is the following: some of the tests need the path to a shared library, which is built together with the tests. in the lib/mylib/tests/Jamfile.v2 I have the following: [...] # our test lib for shared library tests lib test_library : test_library.cpp ; test-suite mylib : # # shared library # [ run shared_library_load_test.cpp ] [ run shared_library_get_symbol_test.cpp ] # # [...] Inside shared_library_*_test.cpp I need something like this: boost::filesystem::path tstlib("bin.v2/libs/mylib/test/mycompiler/test_library.so"); As boost.build decides by itself where to put the binary, i cannot hardcode the path in the source-files.. Is there a way to get the path from boost.build? If not, how could I solve this problem? -- regards dib

3 2

Compilation problem with has_binary_operator.hpp on Mac OSX
by Tim Burgess 12 Feb '14

12 Feb '14

Hi, I'm building a framework project using Xcode 4.6 configured to use the Apple GCC 4.2 compiler (my project also uses wxWidgets, so this compiler is required). Using Boost 1.55.0 I get: cd /Users/tim/Developer/RBSpeech setenv LANG en_US.US-ASCII /Applications/Xcode.app/Contents/Developer/usr/bin/llvm-gcc-4.2 -x objective-c++ -arch x86_64 -fmessage-length=0 -pipe -Wno-trigraphs -fpascal-strings -O0 -Wreturn-type -Wunused-variable -Wuninitialized -Wshorten-64-to-32 -DDEBUG=1 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Develop er/SDKs/MacOSX10.8.sdk -fasm-blocks -mmacosx-version-min=10.6 -gdwarf-2 -fvisibility-inlines-hidden -iquote /Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidkwh bsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/RBSpeech-ge nerated-files.hmap -I/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/RBSpeech- own-target-headers.hmap -I/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/RBSpeech- all-target-headers.hmap -iquote /Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidkwh bsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/RBSpeech-pr oject-headers.hmap -I/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Products/Debug/include -I/users/tim/developer/libraries/wxwidgets/include -I/users/tim/developer/libraries/cryptopp -I/users/tim/developer/libraries/boost_1_55_0 -I/users/tim/developer/sources/surfacereader -I/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/DerivedSo urces/x86_64 -I/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/DerivedSo urces -F/Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidk whbsxvlwng/Build/Products/Debug -I/Users/tim/developer/libraries/wxwidgets/build-debug/lib/wx/include/osx_co coa-unicode-static-2.9 -I/Users/tim/developer/libraries/wxwidgets/include -D_FILE_OFFSET_BITS=64 -D__WXMAC__ -D__WXOSX__ -D__WXOSX_COCOA__ -include /Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidkwh bsxvlwng/Build/Intermediates/PrecompiledHeaders/RBSpeech-Prefix-filshqejewqv wmcnuphmjzrmapcf/RBSpeech-Prefix.pch -c /Users/tim/Developer/RBSpeech/../Sources/SurfaceReader/RBSpeech.mm -o /Users/tim/Library/Developer/Xcode/DerivedData/RBSpeech-gglcnsigefizlfbidkwh bsxvlwng/Build/Intermediates/RBSpeech.build/Debug/RBSpeech.build/Objects-nor mal/x86_64/RBSpeech.o cc1objplus: warning: -Wuninitialized is not supported without -O In file included from /users/tim/developer/libraries/boost_1_55_0/boost/type_traits/has_left_shift .hpp:43, from /users/tim/developer/libraries/boost_1_55_0/boost/lexical_cast.hpp:165, from /Users/tim/Developer/RBSpeech/../Sources/SurfaceReader/RBStringFuncs.hpp:11, from /Users/tim/Developer/RBSpeech/../Sources/SurfaceReader/RBSpeech.h:27, from /Users/tim/Developer/RBSpeech/../Sources/SurfaceReader/RBSpeech.mm:4: /users/tim/developer/libraries/boost_1_55_0/boost/type_traits/detail/has_bin ary_operator.hpp:155: error: expected unqualified-id before 'do' The project uses OSX10.8 as its base SDK, but has OSX10.6 as its deployment target to provide backward compatibility and I made sure that my Boost libraries specified the 10.6 SDK as a minimum. Can anybody advise, please? Best wishes. Tim Burgess

7 11

Confused with the example students_t_single_sample.cpp
by lizy10b 08 Feb '14

08 Feb '14

Hi there, I got a problem with the example "students_t_single_sample.cpp". The corresponding document is at: http://www.boost.org/doc/libs/1_55_0/libs/math/doc/html/math_toolkit/stat_t… Actally, I am confused with the mathematical logic rather than coding. The document presents a table that shows four hypothesis and tests, I am OK with the frist two, but for the third and the fourth ones: The original text: Hypothesis 3: the sample mean is less than the true mean Test 3: Reject if CDF of t > significance level, cdf(dist, t) > alpha I think p-value should be the integral from t to +Infinite: cdf(complement(dist, t)), So reject Hypothesis 3 when cdf(complement(dist, t)) < alpha, or say cdf(dist, t) > 1-alpha The original text: Hypothesis 4: the sample mean is greater than the true mean Reject if complement of CDF of t > significance level: cdf(complement(dist, t)) > alpha Similarly, the p-value should be the integral from -Infinite to t: cdf(dist, t), so reject Hypothesis 4 when cdf(dist, t) < alpha Is that right? Thanks. Zhiyu Li 2014-01-11 lizy10b

3 3

boost::none for boost::shared_ptr
by Chris Stankevitz 03 Feb '14

03 Feb '14

Hello, Does boost::shared_ptr offer a way to create an empty shared pointer without a lot of typing? Perhaps something analogous to boost::none. I am not using c++11. Thank you, Chris == using boost::none; using boost::optional; // declare f(optional<CSomeReallyLongClassName> Item); g(shared_ptr<CSomeReallyLongClassName> pItem); // invoke f with empty object f(none); // invoke g with empty object g(shared_ptr<CSomeReallyLongClassName>());

5 9

inter thread communication with message queues
by Kenneth Adam Miller 31 Jan '14

31 Jan '14

I was reading about message queues with respect to inter thread communication, and I have a specific use case that I want to describe. It's rather complex, so I want to be careful that I design it so that there are no race conditions. Pool A is a buffer (of type 1) handle manager, that feeds buffer handles into thread set 1, and receives old handles from thread set 2. There is only one thread running pool A. Thread set 1 is a set of N threads that fill up buffers of type 1 with regular data. It pushes full buffers to thread set 2. Thread set 2 is a set of M threads that compress buffers of type 1 into data buffers of type 2. Once the buffer of type 1 has be used up, it is cleared and sent back to Pool A. It pulls fresh data buffers of type 2 from Pool B, and sends freshly filled compressed buffers to Pool C. Pool C does something with the buffer, clears it and hands it to Pool B. Can this be done safely using an implementation like what I see here: http://www.justsoftwaresolutions.co.uk/threading/implementing-a-thread-safe… ? Note 1: -= denotes a 1-to-N connect and =- a N-to-1 connect RR = Request reply relationship +--------------------------------------------------------------------+ | | v | Pool A RR Thread Set 1 Router X | PULL-PUSH --==> PULL-read-PUSH ==--> PULL-PUSH --==> PULL Thread Set 2 PUSH \ / +-compress-+ Pool B RR / \ PULL-PUSH --==> PULL PUSH ^ || | || +----------- PUSH-write-PULL <--==++ Pool C Questions: how do I have a separate thread poll on multiple shared message queues? Like, I have a thread pool that both receives requests for buffer handles and that receives old buffer handles to recycle.

3 3

asio/ip/udp.hpp causes MSVC to use std::bind
by Chris Stankevitz 30 Jan '14

30 Jan '14

boost 1.55 VS2012 Update 4 === Can you tell me why the following code fails to compile? It smells as if udp.hpp is causing MSVC to "using namespace std". PS: It doesn't happen if I remove the asio include. PPS: It doesn't happen if g() takes int vs std::string. PPPS: It doesn't happen on GCC Thank you, Chris === #include <boost/bind.hpp> #include <boost/asio/ip/udp.hpp> #include <string> using boost::bind; void g(const std::string&) { } int main() { bind(g, _1); return 0; } === 1>------ Build started: Project: OverlayServer, Configuration: Debug Win32 ------ 1> main.cpp 1>main.cpp(13): error C2668: 'std::bind' : ambiguous call to overloaded function 1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\functional(1387): could be 'std::_Bind<_Forced,_Ret,_Fun,_V0_t,_V1_t,_V2_t,_V3_t,_V4_t,_V5_t,<unnamed-symbol>> std::bind<void,const std::string&,boost::arg<I>&>(_Rx (__cdecl *)(const std::basic_string<_Elem,_Traits,_Alloc>),_Vx0_t)' [found using argument-dependent lookup] 1> with 1> [ 1> _Forced=true, 1> _Ret=void, 1> _Fun=void (__cdecl *const )(const std::string &), 1> _V0_t=boost::arg<1> &, 1> _V1_t=std::_Nil, 1> _V2_t=std::_Nil, 1> _V3_t=std::_Nil, 1> _V4_t=std::_Nil, 1> _V5_t=std::_Nil, 1> <unnamed-symbol>=std::_Nil, 1> I=1, 1> _Rx=void, 1> _Elem=char, 1> _Traits=std::char_traits<char>, 1> _Alloc=std::allocator<char>, 1> _Vx0_t=boost::arg<1> & 1> ] 1> c:\externalpackages\boost_1_55_0\boost\bind\bind_cc.hpp(26): or 'boost::_bi::bind_t<R,F,L> boost::bind<void,const std::string&,boost::arg<I>>(R (__cdecl *)(B1),A1)' 1> with 1> [ 1> R=void, 1> F=void (__cdecl *)(const std::string &), 1> L=boost::_bi::list1<boost::arg<1>>, 1> I=1, 1> B1=const std::string &, 1> A1=boost::arg<1> 1> ] 1> while trying to match the argument list '(overloaded-function, boost::arg<I>)' 1> with 1> [ 1> I=1 1> ] ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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[accumulators] "count" NaN but otherwise ignore it?
by Rhys Ulerich 29 Jan '14

29 Jan '14

Is there a feature within accumulators to count NaNs on extraction but to otherwise ignore them? Maybe some sort of pass filter on incoming data? I've got a situation where I'd like to avoid NaNs clobbering otherwise useful information, but I still want to total count of data seen to include them. The context is a time integrator for a physics simulation. The integrator tracks the number of timesteps. When the physics kicks back a NaN (because something's amiss), I'd like to count the failed timestep but not have the NaN destroy the useful mean of timesteps taken thus far. Thanks, Rhys

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Avoid transitive link dependency
by Dario Ramos 29 Jan '14

29 Jan '14

I wrote a serial port static library using boost::asio. I'm trying to use this library from another project I'm building as a dll, but this second project fails to link: it wants to link with Boost's sytem library. I used PIMPL to remove all boost #includes from my class header, and also tried setting Visual Studio's Link Library Dependencies option set to Yes in my static library. Neither approach worked. I know I can solve this by adding the boost binary directory to the library directories for my dll project, but I'd like to avoid that. The way I see it, only my static library should have a Boost link dependency. I'm using Visual Studio 2012, targetting to Windows XP (v110_xp toolset), and Boost 1.53.0. I asked about this at Stack Overflow if anyone's interested: http://stackoverflow.com/questions/21435666/avoid-link-dependency-with-boost -- *Darío Eduardo Ramos* Meditech S.A. www.meditech.com.ar (+54) 01147603300, Interno 31 Av. Julio A. Roca 3456 Florida Oeste, Bs.As. Argentina

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[Container] any debug renderings for Visual Studio?
by John M. Dlugosz 29 Jan '14

29 Jan '14

When I try to inspect, say, a flat_vector (or anything built on top of it like a flat_map) I can't see the elements in the Watch display. Is there some way to teach VS about that? I seem to remember a long time ago having VS skip things like shared_ptr dereference when stepping through.

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boost condition_variable internals
by Kenneth Adam Miller 29 Jan '14

29 Jan '14

I need to know that boost does not use any kind of locking, mutex or semaphore mechanism within the boost::condition_variable class. I don't know where it is in source, or I would check to make certain. Can someone provide me a yes no verification?

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[offtopic] C++Now 2014 - hotel room available
by Hartmut Kaiser 29 Jan '14

29 Jan '14

I apologize for posting off-topic. Hey all, Unfortunately I will not be able to come to C++Now this year. However I already booked my hotel room at the Aspen Meadows (at the early bird rate!). If anybody is interested in using the hotel reservation, please get in contact with me offline. Thanks! Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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C++Now 2014 Student Volunteer Program Accepting Applications - Please help spread the word
by Bryce Adelstein-Lelbach 28 Jan '14

28 Jan '14

C++Now, presented by Boost in-cooperation with the ACM, is an international gathering of C++ programmers. In 2013, the conference launched a Student/Volunteer Program to enable young coders to attend the conference. This year, we are again are inviting students with an interest in C++ programming to attend the May 12-17, 2014 conference in Aspen, CO as Student/Volunteers. The program is an excellent way for students with any interest in C++ to learn about C++ and make lasting connections with the C++ community. "Attending has truly been one of the most inspirational moments of my life. I had the opportunity to learn, socialize and have a great time in general. I hope to attend this conference yearly now and make a lasting impact in the computer science community." - Grant Mercer, 2013 C++Now Student/Volunteer. "All of the attendees had knowledge to share. Although the talks can be seen online, nothing can compare to being surrounded by over a hundred C++ enthusiasts." - Alex Duchene, 2013 C++Now Student/Volunteer Student/Volunteers will receive free registration. A limited number of applicants will receive stipends for travel expenses. Volunteers will handle various tasks during the conference, such as assisting presenters, setting up presentation rooms, running A/V equipment and helping with the conference picnic. Students from all fields of study are welcome to apply. However, this conference covers advanced C++ topics, and applicants should have ample experience with the C++ programming language and be familiar with general computer science topics. Applications will be accepted until February 15th, 2014. Application decisions will be sent out by March 18th, 2014. You can learn more about the program and some of the students who have participated at http://cppnow.org/volunteer. -- Bryce Adelstein-Lelbach, Student/Volunteer Chair

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Forthcoming Boost.Fiber review
by Nat Goodspeed 28 Jan '14

28 Jan '14

Hi all, The review of Boost.Fiber by Oliver Kowalke is scheduled from Monday, January 6th to January 12th. ----------------------------------------------------- About the library: Boost.Fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperatively. The API contains classes and functions to manage and synchronize fibers similar to Boost.Thread. Each fiber has its own stack. A fiber can save the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (versus threads, which are preemptively scheduled). The running fiber decides explicitly when it should yield to allow another fiber to run (context switching). Boost.Fiberinternally uses coroutines from Boost.Coroutine <http://ok73.funpic.de/boost/libs/coroutine/index.html>; the classes in this library manage, schedule and, when needed, synchronize those coroutines. A context switch between threads usually costs thousands of CPU cycles on x86, compared to a fiber switch with a few hundred cycles. A fiber can only run on a single thread at any point in time. docs: http://ok73.funpic.de/boost/libs/fiber/doc/html/index.html<http://ok73.ok.funpic.de/boost/libs/coroutine/doc/html/> git: https://github.com/olk/boost-fiber src: http://ok73.ok.funpic.de/boost.fiber.zip<http://ok73.ok.funpic.de/boost.coroutine.zip> --------------------------------------------------- Naturally, you need not wait until the review formally opens to start reviewing the Fiber library. Please always state in your review whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Nat Goodspeed Boost.Fiber Review Manager ------------------------------

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making a geometry half closed
by Sean Farrow 27 Jan '14

27 Jan '14

Hi, >From what I understand any boost geometry is fully closed. Is there a way of making a geometry half closed, such that the bottom row is not included? I'm needing to do this with a Box2D$Values. Any help appreciated. Cheers Sean.

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[Geometry] Issues when registering a windows point type
by Sean Farrow 26 Jan '14

26 Jan '14

Hi, I'm having an Issue when trying to register a windows POINT type. I'm registering the Point structure from windef.h as follows: BOOST_GEOMETRY_REGISTER_POINT_2D(POINT, LONG, boost::geometry::cs::cartesian, x, y); I'm getting the following in my build log: 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2870: 'boost' : a namespace definition must appear either at file scope or immediately within another namespace definition 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2913: explicit specialization; 'boost::geometry::traits::tag' is not a specialization of a class template 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2059: syntax error : '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '{' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2447: '{' : missing function header (old-style formal list?) 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2913: explicit specialization; 'boost::geometry::traits::dimension' is not a specialization of a class template 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2059: syntax error : '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C3083: 'mpl': the symbol to the left of a '::' must be a type 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2039: 'int_' : is not a member of 'boost' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2913: explicit specialization; 'boost::geometry::traits::coordinate_type' is not a specialization of a class template 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2059: syntax error : '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2913: explicit specialization; 'boost::geometry::coordinate_system' is not a specialization of a class template 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2059: syntax error : '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C3083: 'cs': the symbol to the left of a '::' must be a type 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2039: 'cartesian' : is not a member of 'boost::geometry' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2143: syntax error : missing ';' before '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2913: explicit specialization; 'boost::access' is not a specialization of a class template 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2059: syntax error : '<' 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): error C2267: 'set' : static functions with block scope are illegal 1>c:\work\pantheon studios\o2\disesupport\supportfunctions.cpp(37): fatal error C1903: unable to recover from previous error(s); stopping compilation I'd rather not have to define my own point structure if at all possible! Any help appreciated to solve this. Cheers Sean.

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