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

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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?

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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

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