August 2013 - Boost-users - lists.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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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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Server failing when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active
by Gonzalo Garramuno 22 Jan '14

22 Jan '14

Trying to track down when the socket closes on my program, I turned on asio debugging. Server fails when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active. Its stack trace is: g Scanning dependencies of target mrViewer [ 9%] Building CXX object mrViewer/src/CMakeFiles/mrViewer.dir/core/mrvServer.o Linking CXX executable ../../../bin/mrViewer [100%] Built target mrViewer # gga@gga-laptop1 /media/Linux/code/applications/mrViewer # mar ene 01 10:04 [8] $ mrViewer /media/Linux/movies/Tangled.mov [opengl] Using hardware shader profile: NVidia NV30 [opengl] mrViewer supports YUV images through shaders. [psql] Connected to database 'assets2d_development'. The code: boost::asio::io_service io_service; tcp::endpoint listen_endpoint(tcp::v4(), s->port); server rp(io_service, listen_endpoint, s->ui); io_service.run(); fails with: @asio|1357088683.200673|0|socket@0x7f303d8d2d00.close Got signal 11, faulty address is 0x1, from 0x4d222a [bt] Execution path: [bt] mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) [0x4d222a] [bt] mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) [0x4d222a] [bt] mrViewer() [0x4dd2c9] [bt] mrViewer(_ZN3mrv13server_threadEPKNS_10ServerDataE+0x408) [0x4e0e58] [bt] /usr/lib/libboost_thread.so.1.48.0(+0xdda9) [0x7f304e191da9] [bt] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a) [0x7f304f7f0e9a] [bt] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f304da1ccbd] without the #define the code works reliably except sometimes the socket closes unexpectedly.

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Question for Boost.Threads and Boost.Test
by young 20 Jan '14

20 Jan '14

According to Boost document, Boost.Test can only be statically linked. Boost.Threads can only be dynamically linked. Then what boost_unit_test_framework-vc100-mt-1_53.lib for? Is it for dynamically linked dll? what libboost_thread-vc100-mt-1_53.lib for? Is it for static library? -- View this message in context: http://boost.2283326.n4.nabble.com/Question-for-Boost-Threads-and-Boost-Tes… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Test] Where to learn about boost::itest::mock_object?
by Mateusz Loskot 20 Jan '14

20 Jan '14

Hi, I'm looking for a simple mocking library to use together with Boost.Test. There is Turtle (aka Boost.Mock) and googlemock. During retrospection of the big thread on Boost.Test future [1], I found this curious post by Gennadiy [2] about mock_object. I had no idea such facility lives in Boost.Test and it looks it's been there for very long time. I can't find any documentation about mock_oboject, only a couple of examples. So, I have a few questions: Is the mock_object an internal feature or is it dedicated (and ready) to use by Boost.Test users? What are basic features of this mocking facility? How does it compare to Turtle or googlemock? [1] http://thread.gmane.org/gmane.comp.lib.boost.devel/234297 [2] http://thread.gmane.org/gmane.comp.lib.boost.devel/234297/focus=234621 [3] find /home/mloskot/dev/boost/_svn/trunk/libs/test -type f | xargs grep mock_object Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Does Boost.Test cover 'golden file approach'?
by Journeyer J. Joh 13 Jan '14

13 Jan '14

Hello, I know almost nothing about 'golden file approach'. http://weblogs.java.net/blog/alexeyp/archive/2007/02/testing_command.html >From this blog, you can find the term 'golden file approach'. I want to know if Boost.Test cover this kind of testing. Can I implement 'golden file approach' with Boost.Test? If so please provide me more information about it. Thank you very much. ---------------------------------------- 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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[Test] using output_test_stream to compare in the middle of a file
by Lloyd 13 Jan '14

13 Jan '14

Hi, We need to test a function which reads a "record" from a binary file. We want to compare the buffer with the "record" in input file.We know the offset of the record in input file. How can we compare the output_test_stream with a certain offset (and length) of the file? or is there any alternative for this? Thanks, Lloyd

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Boost.Test segfault clang++3.3 macports cmake
by Dave Gomboc 13 Jan '14

13 Jan '14

I am getting a segmentation fault when attempting to use Boost.Test. I suspect that I don't have something set up correctly -- your assistance in remedying this would be appreciated. I am using clang++-mp-3.3 as installed by MacPorts on OS X 10.8.4. Here's the crash, which occurs after Boost.Test reports "*** No errors detected". Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: 13 at address: 0x0000000000000000 0x000000010006f6d6 in boost::unit_test::test_unit::~test_unit () (gdb) bt #0 0x000000010006f6d6 in boost::unit_test::test_unit::~test_unit () #1 0x000000010003bb5f in boost::unit_test::master_test_suite_t::~master_test_suite_t () #2 0x000000010003bcdd in boost::unit_test::framework_impl::~framework_impl () #3 0x00007fff8f465307 in __cxa_finalize () #4 0x00007fff8f466f57 in exit () #5 0x00007fff96ddc7e8 in start () (gdb) Here's a somewhat simplified version of what I have: ==== UseBoostUnitTestFramework.hpp ==== #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wall" #pragma clang diagnostic ignored "-Wdisabled-macro-expansion" #pragma clang diagnostic ignored "-Wexit-time-destructors" #pragma clang diagnostic ignored "-Wextra-semi" #pragma clang diagnostic ignored "-Wglobal-constructors" #pragma clang diagnostic ignored "-Wmissing-prototypes" #pragma clang diagnostic ignored "-Wsign-conversion" #pragma clang diagnostic ignored "-Wundef" #pragma clang diagnostic ignored "-Wweak-vtables" #include <boost/test/unit_test.hpp> #pragma clang diagnostic pop ==== HaveBoostUnitTestFrameworkDefineMain.cpp ==== #define BOOST_TEST_MODULE All_Tests #include "UseBoostUnitTestFramework.hpp" /* commenting out the next 3 lines makes no difference */ namespace boost { namespace unit_test { namespace framework { master_test_suite_t & master_test_suite(); } } } // namespace boost::unit_test::framework ==== CMakeLists.txt ==== cmake_minimum_required(VERSION 2.8.10 FATAL_ERROR) cmake_policy(VERSION 2.8.10) project (Foo) add_definitions(-DBOOST_TEST_DYN_LINK) add_library (foo SHARED Foo1.hpp more files... UseBoostUnitTestFramework.hpp Foo1.cpp more files... ) find_package(Boost COMPONENTS unit_test_framework REQUIRED) include_directories(${Boost_INCLUDE_DIRS}) file(GLOB_RECURSE test_source_files *.unit_tests.cpp) link_directories(${Boost_LIBRARY_DIRS}) add_executable(all_tests HaveBoostUnitTestFrameworkDefineMain.cpp ${test_source_files}) target_link_libraries(all_tests foo ${Boost_UNIT_TEST_FRAMEWORK_LIBRARY} ) set(CTEST_OUTPUT_ON_FAILURE TRUE) enable_testing() add_test(all_tests all_tests) set(CMAKE_C_COMPILER "clang-mp-3.3") set(CMAKE_C_FLAGS "-Weverything --std=c11 -O3 -DNDEBUG") set(CMAKE_CXX_COMPILER "clang++-mp-3.3") set(CMAKE_CXX_FLAGS "-ferror-limit=1 --std=c++1y -stdlib=libc++ -Weverything -Wno-c++98-compat -Wno-c++98-compat-pedantic -Wno-padded -O3 -DNDEBUG") ==== Foo1.hpp ==== (has declarations, but nothing that depends on Boost at all -- nor does any other non-test file) ==== Foo1.cpp ==== (has definitions, but nothing that depends on Boost at all -- nor does any other non-test file) ====Foo1.unit_tests.cpp ==== #include "Foo1.hpp" #include <string> #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wglobal-constructors" #include "UseBoostUnitTestFramework.hpp" BOOST_AUTO_TEST_SUITE(Bar1) BOOST_AUTO_TEST_CASE(foobar1) { BOOST_CHECK_EQUAL(std:string("a"), std::string("a")); } BOOST_AUTO_TEST_CASE(foobar2) { BOOST_CHECK_EQUAL(true, true); } BOOST_AUTO_TEST_SUITE_END() BOOST_AUTO_TEST_SUITE(Bar2) BOOST_AUTO_TEST_CASE(barfoo1) { BOOST_CHECK_EQUAL(1, 1); } BOOST_AUTO_TEST_CASE(barfoo2) { BOOST_CHECK_EQUAL(0, 0); } BOOST_AUTO_TEST_SUITE_END() #pragma clang diagnostic pop

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[boost.test] How to register custom exception for auto test?
by Jörg Becker 13 Jan '14

13 Jan '14

Hi, I'm using the test library of boost 1.49.0 for my unit tests. It works fine so fare, but if my program throws an error, I get the default error message unknown location(0): fatal error in "excption1_test": unknown type, witch hides the original error message. I tried to register an error translator, but without success. Here is what I tried (modified test/test/custom_exception_test.cpp to use auto test with global fixture): #define BOOST_TEST_MODULE "boost test custom_exception_test" #include <boost/test/unit_test.hpp> #include <boost/test/unit_test_monitor.hpp> using namespace boost::unit_test; BOOST_AUTO_TEST_SUITE( custom_exception_testsuite ) struct my_exception1 { explicit my_exception1( int res_code ) : m_res_code( res_code ) {} int m_res_code; }; void throw_my_exception1() { throw my_exception1( 12 ); } void my_exception1_translator( my_exception1 ) { BOOST_TEST_MESSAGE( "Caught my_exception1" ); } class my_config { public: my_config () { unit_test_monitor.register_exception_translator<my_exception1>( &my_exception1_translator ); } }; BOOST_GLOBAL_FIXTURE( my_config ) BOOST_AUTO_TEST_CASE( excption1_test ) { throw_my_exception1(); } BOOST_AUTO_TEST_SUITE_END() Can anybody tell me what I'm missing? Thanks, Jörg

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Fwd: support for bjam projects in IDE
by Witold E Wolski 06 Dec '13

06 Dec '13

Hi, I will have to work on bjam based project (rather big). I normally use QT Creator for programming and work with cmake based project. I could't find any hint how to set up an bjam project to work with QT neither information about any IDE which supports bjam. Do boost developer use vim and debug using gdb only? Actually the other guys on the project wrote some python scripts which parse bjam output to generated vcproj files :-@ I would be happy to hear from someone who are happy using bjam with qtcreator or any other IDE for larger projects and how to set this up. All my searches so far regarding bjam return almost exclusively FUD (http://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt) but looking at the Jamroot.jam file of the project (more than 1000 lines) I am inclinded to believe it. ;-( -- Witold Eryk Wolski -- Witold Eryk Wolski

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Max Boost Fusion tuple parameters
by Rodrigo Madera 15 Sep '13

15 Sep '13

Hello, What is the maximum Boost Fusion tuple param count? I was thinking of using it for about 200-300 elements. Anyone done this? I've heard of defines for this, but never actually *knew* of anyone actually doing it. Thanks, Rodrigo Madera

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Too many EOF's using boost::asio
by ustulation 13 Sep '13

13 Sep '13

I have a TCP server and client with following read and write functions: ----------------- Writes ---------------------- void SomeClass::startWrite() { //m_writeBuffer is boost::asio::streambuf..m_writeQueue is std::deque<std::string> m_writeBuffer.sputn(&m_writeQueue.at(0)[0], m_writeQueue.at(0).size()); //m_objStrandWrite is boost::asio::strand boost::asio::async_write( getSocket(), m_writeBuffer, m_objStrandWrite.wrap([this](const boost::system::error_code &e, std::size_t bytesTxd){writeHandler(e, bytesTxd);}) ); } void SomeClass::writeHandler(const boost::system::error_code &refErrorCode, std::size_t bytesTxd) { if(!m_bIsStopped) { m_writeQueue.pop_front(); if(refErrorCode) { if(refErrorCode != boost::asio::error::operation_aborted) { std::cerr << "Write Error: " << refErrorCode.message() << std::endl; stop(); } } else { if(!m_writeQueue.empty()) { startWrite(); } } } } ------------------- Reads ----------------- void SomeClass::startRead() { //m_readBuffer is boost::asio::streambuf..m_objStrandRead is boost::asio::strand boost::asio::async_read_until( getSocket(), m_readBuffer, m_szTermString, m_objStrandRead.wrap([this](const boost::system::error_code &e, std::size_t bytesRxd){readHandler(e, bytesRxd);}) ); } void SomeClass::readHandler(const boost::system::error_code &refErrorCode, std::size_t bytesRxd) { if(!m_bIsStopped) { if(refErrorCode) { if(refErrorCode != boost::asio::error::operation_aborted) { std::cerr << "Read error: " << refErrorCode.message() << std::endl; stop(); } } else { if(bytesRxd) { std::string szRxdData; szRxdData.resize(bytesRxd); m_readBuffer.sgetn(&szRxdData[0], bytesRxd); } startRead(); } } } I get very frequent End Of File (EOF) error on client's read. It is not always but frequent. I am running a threadpool by asking multiple std::threads to execute io_service::run() which never quits until io_service::stop() is called. The data given by the server is almost never more than 5MB. As you see in the code, for any error I call stop() which shuts down the connection gracefully. <Q> *Is there something wrong I'm doing because I see no reason for EOF error. Why should the server close/shutdown the connection?* The code does not do that explicitly. Anyway it is random - out of 10 times maybe 5 are successful reads and 5 become EOF's and I have to restart my client executable to connect again in each of those cases. Other sockets don't do that - eg., I've tested with QTcpSocket of Qt framework and it works all the time (no randomness). -- View this message in context: http://boost.2283326.n4.nabble.com/Too-many-EOF-s-using-boost-asio-tp465117… Sent from the Boost - Users mailing list archive at Nabble.com.

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using boost with net-snmp
by moshe levi 12 Sep '13

12 Sep '13

I wrote an example on how to integrate net-snmp with boost. please checkout http://blog-moshe.blogspot.co.il/

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Boost program option parsing issue.
by Vivek Anand 07 Sep '13

07 Sep '13

Hi All, I am using program option for my program. Here is my code snippet string inputFile, outputFile; /* Populate command line arguments */ po::options_description desc("Usage: KDMGenerator [OPTIONS]"); { desc.add_options() ("help", "prints this message") ( "input-file", po::value<string>(&inputFile), "input file name" ) ( "output-file", po::value<string>(&outputFile), "output file name"); } po::variables_map vm; po::store(po::parse_command_line(argc, argv, desc), vm); po::notify(vm); if (vm.count("help") || !vm.size()) { cout <<desc; return 0; } if(vm.count("input-file")) { cout << "Input file :" << inputFile << '\n'; } if(vm.count("output-file")) { cout << outputFile << '\n'; } The issue I am facing is that if i I call my program without passing value for input file, something like ./myapp --input-file --output-file out.txt I get Input file: --output-file i.e the value "--output-file" get stored in inputFile and vm.count("output-file") returns zero. Is this the desired behavior? Is there any workaround for this? -- Vivek,

2 4

[BGL] Having a cost function as weight map
by Maxime van Noppen 06 Sep '13

06 Sep '13

Hi, I can't find how to do this pretty basic thing : having a function instead of a field to compute the cost of edges for various path finding algorithms. I couldn't find the answer in the documentation and Google was of no help. Did I miss something obvious ? Example : ------------------- #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> struct my_edge { double cost() const { return cost_ * 2; } double cost_; }; struct my_node { }; int main() { typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::directedS, my_node, my_edge > graph_t; typedef boost::graph_traits<graph_t>::vertex_descriptor vertex_t; graph_t graph; vertex_t v /*= ... */; using boost::weight_map; // Works : boost::dijkstra_shortest_paths(graph, v, weight_map(boost::get(&my_edge::cost_, graph))); // Doesn't compile : //boost::dijkstra_shortest_paths(graph, v, // weight_map(boost::get(&my_edge::cost, graph))); } ------------------- Thanks ! -- Maxime

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[chrono] float-based milliseconds?
by Michael Powell 31 Aug '13

31 Aug '13

Hello, Or any of the chrono-steady-clock-based time units... I am noticing some what appear to be rounding errors outputting resulting millisecond values using the boost::chrono::milliseconds(x). It's a design-decision, most if not all of our floating-point values are single-precision-float, don't need to be double-precision-float. When we output the milliseconds(x).count() values, however, what I am finding is that the values are sometimes inaccurate, the same value in 3.0, for instance, output as 2.99995, stuff like this. Is there a way to tell milliseconds what precision floating point it is? float or double? We are targeting ARM, BTW, without hardware floating point support, which is the main reason, I'd like to keep things single-precision float, if at all possible. Thank you... Regards, Michael Powell

3 6

libboost_thread-vc80-mt-1_54.lib
by John Emmas 30 Aug '13

30 Aug '13

A few months ago I downloaded 'boost_1_54_0.zip' which I probably obtained from Sourceforge:- http://sourceforge.net/projects/boost/files/boost/1.54.0/ I'm using libboost with Visual C++ 8 and up to now the only things I've needed from it are 'boost::regex' and 'boost::shared_ptr'. However I'm now building a 3rd party library which seems to want to link to the above library (libboost_thread-vc80-mt-1_54.lib). I'm not sure whether it's a static library or the symbols library for a DLL. Either way, the zip file I downloaded doesn't seem to contain it (nor any other libs or DLLs AFAICT). Q1) Is there some other web site I need to visit in order to get the pre-built binaries? Q2) I know from past experience that pre-built boost binaries sometimes require quite obscure versions of the MSVC runtime. That was the case with boost::regex so after a bit of advice from this mailing list, I ended up making a VC project and building it myself. I don't mind doing the same thing for boost::thread - but I wondered if there was already a suitable project available somewhere? I don't want to re-invent the wheel if a VC project already exists! Thanks. John

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[boost-users][tuple] Tuple::get<0> as std::mem_fun_ref
by Miklós Tóth 30 Aug '13

30 Aug '13

Hi! I have a problem with std::mem_fun_ref and boost::tuple. Here is my code: I have small LevelSetter class. It makes a level vector indexed by a transform_iterator value. template <typename LevelType> class LevelSetter { private: int nmb_of_elements; public: LevelSetter(int nmb_of_elements_) : nmb_of_elements(nmb_of_elements_) {} template <typename TrRange> std::vector<LevelType> set(TrRange range) { typedef typename TrRange::first_type TrIter; std::vector<LevelType> levels(nmb_of_elements); for (TrIter it = range.first; it != range.second; ++it) { levels[*it] = 0.0; } // much more complicated code return levels; } }; Let's call it: class MemFunRefTest { private: typedef float Scalar; typedef boost::tuple<int, Scalar> Tuple; typedef std::vector<Tuple> Fwd; typedef Fwd::iterator FwdIter; typedef std::pair<FwdIter, FwdIter> FwdRange; Fwd elements; public: MemFunRefTest() { elements.push_back(Tuple(0, 400.0)); elements.push_back(Tuple(1, 120.0)); elements.push_back(Tuple(2, 150.0)); } void fun() { FwdRange element_range = std::make_pair(elements.begin(), elements.end()); LevelSetter<Scalar> setter(elements.size()); setter.set(std::make_pair( boost::make_transform_iterator( element_range.first, std::mem_fun_ref(&Tuple::get<0>) ), boost::make_transform_iterator( element_range.second, std::mem_fun_ref(&Tuple::get<0>) ) ) ); } }; When I try to compile i get: error: call of overloaded 'mem_fun_ref(<unresolved overloaded function type>)' is ambiguous candidates are: c:\mingw-4.6\bin\..\lib\gcc\i686-pc-mingw32\4.6.1\..\..\..\..\include\c++\4.6.1\bits\stl_function.h:697: std::mem_fun_ref_t<_Ret, _Tp> std::mem_fun_ref(_Ret (_Tp::*)()) [with _Ret = int&, _Tp = boost::tuples::cons<int, boost::tuples::cons<float, boost::tuples::null_type> >] c:\mingw-4.6\bin\..\lib\gcc\i686-pc-mingw32\4.6.1\..\..\..\..\include\c++\4.6.1\bits\stl_function.h:702: std::const_mem_fun_ref_t<_Ret, _Tp> std::mem_fun_ref(_Ret (_Tp::*)()const) [with _Ret = const int&, _Tp = boost::tuples::cons<int, boost::tuples::cons<float, boost::tuples::null_type> >] What am I missing? Thanks, Miklos

2 3

[typeof] registering class templates whose NTTPs depend on other TPs
by Cromwell Enage 29 Aug '13

29 Aug '13

Hi, all. Using Boost.Typeof, how would I register the following class template? ['' template <typename foo, foo bar> struct baz { }; ''] Any help would be appreciated. Cromwell D. Enage

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