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Mutex synchronised wrapper class for boost::interprocess shared memory vector of strings
by Riskybiz 24 Jun '13

24 Jun '13

I'm trying to create a wrapper class to control a managed shared memory segment using Boost::Interprocess. I'm having trouble reading data from the shared memory vector of strings... When the vector is instantiated in the managed shared segment I place in the first vector element a test string; "testing testing 1 2 3". Immediately after placing it there and in the scope of the same code block I can access the vector element and print out the string using std::cout. However when I try to read the vector element using the read() function the test program crashes. The problem is with the line: std::string stdStr = sharedSegmentVector->at(index).c_str(); Question is how to fix this? I'm confused because at instantiation time this same code will access the shared memory vector; later on in the read() function it will not. I've as yet been unable to test the write() function; because I can't yet read() the vector! Any help to get this working is much appreciated, With thanks, Riskybiz Class Definition: #ifndef SHARED_MEMORY_WRAPPER_H//if not defined already #define SHARED_MEMORY_WRAPPER_H//then define it #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/sync/named_mutex.hpp> #include <iostream> #include <stdexcept> using namespace boost::interprocess; class SharedMemoryWrapper { public: SharedMemoryWrapper(const std::string &name, bool server) : m_name(name), m_server(server) { if (server) { named_mutex::remove("named_mutex"); shared_memory_object::remove(m_name.c_str()); //Create shared memory managed_shared_memory m_segment(create_only, m_name.c_str(), 10000); //Create allocators CharAllocator charallocator(m_segment.get_segment_manager()); StringAllocator stringallocator(m_segment.get_segment_manager()); //This string is in only in this process (the pointer pointing to the //buffer that will hold the text is not in shared memory). //But the buffer that will hold "this is my text" is allocated from //shared memory MyShmString mystring(charallocator); mystring = "testing testing 1 2 3"; //This vector is fully constructed in shared memory. All pointers //buffers are constructed in the same shared memory segment //This vector can be safely accessed from other processes. MyShmStringVector *sharedSegmentVector = m_segment.construct<MyShmStringVector>("sharedSegmentVector")(stringallocato r); sharedSegmentVector->push_back(mystring); std::string outStr = sharedSegmentVector->at(0).c_str(); std::cout << "Shared Memory Vector Instantiated: Index 0 Data is: " << outStr << std::endl; } else { //Open the shared segment managed_shared_memory m_segment(open_only, name.c_str()); //Find the vector using the c-string name and open it MyShmStringVector *sharedSegmentVector = m_segment.find<MyShmStringVector>("sharedSegmentVector").first; } m_mutex = new named_mutex(open_or_create, "named_mutex"); } ~SharedMemoryWrapper() { if (m_server) { named_mutex::remove("named_mutex"); //Destroy the vector from the managed_shared_memory //m_segment->destroy_ptr(sharedSegmentVector);//This will free all strings that the vector contains m_segment->destroy<MyShmStringVector>("sharedSegmentVector");//Destroy the vector //Is it necessary to destroy the allocators here? //Remove the managed_shared_memory; this may fail if the memory does not exist or is mapped or opened by another process shared_memory_object::remove(m_name.c_str()); } delete m_mutex; delete m_segment; } //Writer void write(const std::string &in) { try { CharAllocator charallocator(m_segment->get_segment_manager()); scoped_lock<named_mutex> lock(*m_mutex); MyShmString shmStr(in.c_str(), charallocator); sharedSegmentVector->push_back(shmStr); } catch(...) { std::cout << "Error in SharedMemoryWrapper::write(): unknown error" << std::endl; } } //Reader std::string read(int index) { try { scoped_lock<named_mutex> lock(*m_mutex); std::cout << "Shared Memory Vector Entered Read(), Passed Index: " << index << std::endl; std::string stdStr = sharedSegmentVector->at(index).c_str(); std::cout << "Shared Memory Vector Read At: Index" << index << "Data is: " << stdStr << std::endl; return stdStr; } catch(std::range_error err) { std::cout << "Error in SharedMemoryWrapper::read(): range_error" << std::endl; } catch(...) { std::cout << "Error in SharedMemoryWrapper::read(): unknown error " << std::endl; } return "ERROR IN SharedMemoryWrapper::read()"; } private: //Typedefs typedef boost::interprocess::allocator<char, managed_shared_memory::segment_manager> CharAllocator; typedef boost::interprocess::basic_string<char, std::char_traits<char>, CharAllocator> MyShmString; typedef boost::interprocess::allocator<MyShmString, managed_shared_memory::segment_manager> StringAllocator; typedef boost::interprocess::vector<MyShmString, StringAllocator> MyShmStringVector; bool m_server; std::string m_name; managed_shared_memory *m_segment; MyShmStringVector *sharedSegmentVector; named_mutex *m_mutex; };//class #endif//header guard Test Programme: #include "stdafx.h" #include "SharedMemoryWrapper.h" #include <iostream> #include <string> int main(int argc, char *argv[]) { SharedMemoryWrapper *smw = new SharedMemoryWrapper("SharedMemory1", true); std::string outStr = smw->read(0); std::cout << outStr << std::endl; return 0; }

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Re: [Boost-users] Mutex synchronised wrapper class for boost::interprocess shared memory vector of strings
by Riskybiz 24 Jun '13

24 Jun '13

Date: Wed, 19 Jun 2013 22:05:32 +0200 From: Ion Gazta?aga <igaztanaga(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Mutex synchronised wrapper class for boost::interprocess shared memory vector of strings Message-ID: <51C20F0C.8090408(a)gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed El 18/06/2013 16:28, Riskybiz escribi?: > I'm trying to write a wrapper class in C++ to give mutex synchronised > interprocess access to a shared memory vector of strings. This is my first > foray into boost::interprocess and allocators are proving something of a > mystery. > > Is anyone able to see why on compilation I get the error: When you build any container in shared memory it must be constructed with an allocator. Change your push function to (not charallocator is passed to MyShmString): void push(const std::string & in) { CharAllocator charallocator(m_segment->get_segment_manager()); scoped_lock<named_mutex> lock(*m_mutex); MyShmString inStr(in.c_str(), charallocator); sharedSegmentVector->push_back(inStr); } Best, Ion Thanks for the reply Ion. I'm now having trouble reading from the vector in the shared memory. I get an exception when calling read(0) or read(1). What I'm trying to do is read "testing testing 123" from the first element of the sharedSegmentVector. Is it necessary to use some particular type conversion technique in the reader function to access a sharedSegmentVector string element? Any help to get this working is much appreciated; I've been trying for more than a month to get to this point! Code below..... Thanks Riskybiz #ifndef SHARED_MEMORY_WRAPPER_H//if not defined already #define SHARED_MEMORY_WRAPPER_H//then define it #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/sync/named_mutex.hpp> using namespace boost::interprocess; class SharedMemoryWrapper { public: SharedMemoryWrapper(const std::string &name, bool server) : m_name(name), m_server(server) { if (server) { named_mutex::remove("named_mutex"); shared_memory_object::remove(m_name.c_str()); //Create shared memory managed_shared_memory m_segment(create_only, m_name.c_str(), 10000); //Create allocators CharAllocator charallocator(m_segment.get_segment_manager()); StringAllocator stringallocator(m_segment.get_segment_manager()); //This string is in only in this process (the pointer pointing to the //buffer that will hold the text is not in shared memory). //But the buffer that will hold "this is my text" is allocated from //shared memory MyShmString mystring(charallocator); mystring = "testing testing 1 2 3"; //This vector is fully constructed in shared memory. All pointers //buffers are constructed in the same shared memory segment //This vector can be safely accessed from other processes. MyShmStringVector *sharedSegmentVector = m_segment.construct<MyShmStringVector>("sharedSegmentVector")(stringallocato r); sharedSegmentVector->push_back(mystring); } else { //Open the shared segment managed_shared_memory m_segment(open_only, name.c_str()); //Find the vector using the c-string name and open it MyShmStringVector *sharedSegmentVector = m_segment.find<MyShmStringVector>("sharedSegmentVector").first; } m_mutex = new named_mutex(open_or_create, "named_mutex"); } ~SharedMemoryWrapper() { if (m_server) { named_mutex::remove("named_mutex"); //Destroy the vector from the managed_shared_memory m_segment->destroy_ptr(sharedSegmentVector);//This will free all strings that the vector contains m_segment->destroy<MyShmStringVector>("sharedSegmentVector");//Destroy the vector //Is it necessary to destroy the allocators here? //Remove the managed_shared_memory; this may fail if the memory does not exist or is mapped or opened by another process shared_memory_object::remove(m_name.c_str()); } delete m_mutex; delete m_segment; } //Writer void write(const std::string &in) { CharAllocator charallocator(m_segment->get_segment_manager()); scoped_lock<named_mutex> lock(*m_mutex); MyShmString shmStr(in.c_str(), charallocator); sharedSegmentVector->push_back(shmStr); } //Reader std::string read(long index) { CharAllocator charallocator(m_segment->get_segment_manager()); scoped_lock<named_mutex> lock(*m_mutex); MyShmString shmStr(sharedSegmentVector->at(index), charallocator); std::string stdStr = std::string(shmStr.begin(), shmStr.end()); return stdStr; } private: //Typedefs typedef boost::interprocess::allocator<char, managed_shared_memory::segment_manager> CharAllocator; typedef boost::interprocess::basic_string<char, std::char_traits<char>, CharAllocator> MyShmString; typedef boost::interprocess::allocator<MyShmString, managed_shared_memory::segment_manager> StringAllocator; typedef boost::interprocess::vector<MyShmString, StringAllocator> MyShmStringVector; bool m_server; std::string m_name; managed_shared_memory *m_segment; MyShmStringVector *sharedSegmentVector; named_mutex *m_mutex; };//class #endif//header guard

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[interprocess]shared_memory_object stores content in disk?
by Adrian Yu 24 Jun '13

24 Jun '13

I'm training multiple networks based on a single database. So to accelerate speed and reduce disk reading, I use shared_memory_object class provided by boost. Since the lab workstation is currently unavailable, I migrated my code to my personal computer. On the lab workstation, the host program successfully reads all data to memory. But on my PC, strangely it creates a file on system drive rather than storing the data in memory. The whole database is about 3.7 GB; the lab workstation has 32 GB memory and runs Windows Server 2008 R2; my PC has 8 GB memory and runs Windows 7. There should be enough memory to store the data. So why? Are there certain ways to force the program to keep all data in memory?

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[Interprocess] Allocation algorithms
by Oodini 24 Jun '13

24 Jun '13

Hello, I need to allocate and fill about 10 big memories areas (several Gb) at the startup of my program. The data will never be modified or freed after during the program lifetime, and will be *only read* an other processes. What allocation algorithm should I take from the ones provided by the library ? Should I create a new one, more efficient (no reallocations, no race conditions...) ? Thanks.

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[Interprocess] Minimal size of a managed_shared_memory
by Oodini 24 Jun '13

24 Jun '13

Hello, A managed_shared_memory is a typedef for a basic_managed_shared_memory using rbtree_best_fit as allocation algorithm. In the documentation : http://www.boost.org/doc/libs/1_53_0/doc/html/interprocess/memory_algorithm… It is said at the and of the page : "In most 32 systems with 8 byte alignment the minimum size of a block is 24 byte". I am on Windows XP SP3 32 bits. The alignement is 8 byte. But if I create a managed_shared_memory with a size lesser than 120 bytes, my app crashes. This value comes from several get_min_size function, the deepest being in the rbtree_best_fit class. So I wonder which value we can grant to the documentation above. How are the 120 bytes used ?

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Boost::Interprocess Documentation request
by Riskybiz 24 Jun '13

24 Jun '13

In the Boost::Interprocess documentation and under the heading "Where is this being allocated?"; is an example of how to create a vector of strings in a managed_shared_memory segment. Link to Boost::Interprocess documentation here: http://www.boost.org/doc/libs/1_53_0/doc/html/interprocess/allocators_contai ners.html#interprocess.allocators_containers.containers_explained Please could this example be extended to demonstrate; 1. How to add string elements to the shared memory vector from a different process? 2. How to access and copy strings from the shared memory vector from a different process? This really would be invaluable to people trying to use Boost::Interprocess for the first time! My particular project has ground to a halt for over a month simply trying to get a working implementation of a Boost::Interprocess mutex synchronised shared memory vector of strings. I would like one process to add strings to the shared memory vector and several other processes to read string data from the vector. Right now I don't know if I'll ever get it to work! Running out of ideas here! Hope someone can help. Thanks, Riskybiz.

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[property_tree] Serializing ptree to/from JSON
by Michael Powell 24 Jun '13

24 Jun '13

Hello, I am writing some code to serialize a package to/from JSON. Overall, it is working well, except for what appears to be a weak link in the ptree chain of events. I take a POCO (for all intents) and populate a ptree, then parse that to JSON using the property_tree JSON parser. No problem. Then I take that same string and want to parse it into another ptree. In and of itself, seems like it is no problem. The new ptree has a count, so I gather the parse worked. However, when I try to use ptree.count(path), or ptree.find(path), neither of these work. They are returning 0 or not_found(), respectively. I may be able to bypass that check for the moment and run it through ptree.get<Type>(path) for the time being, but that seems less desirable. Any insights on ptree along these lines? Thanks! Regards, Michael Powell

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[FunctionTypes] Getting functor/lambda parameters (VS2012)
by Mateusz Loskot 23 Jun '13

23 Jun '13

Hi, I'm using C++ compiler from the latest VS2012. I'm trying this simple technique to determined type of functor or lambda call parameter, it works well: #include <boost/function_types/parameter_types.hpp> int main() { auto foo = [](int) -> void {}; typedef decltype(foo) foo_type; typedef boost::function_types::parameter_types < decltype(&foo_type::operator()) >::type parameter_types; } Next, I move the typedef into class template, in constructor body, it works well too: template <typename T> struct A { A(T t) { typedef typename boost::function_types::parameter_types < decltype(&T::operator()) >::type parameter_types; } }; Finally, I move further with the technique, so I can access parameter types within class template scope: template <typename T> struct B { typedef typename boost::function_types::parameter_types < decltype(&T::operator()) >::type parameter_types; }; This example does compile with clang 3.4 (svn trunk) and GCC 4.8.1, but it does not compile with Visual C++ 11.0. Does anyone understand what C++11 feaure VS2012 is lacking so it prevents compilation of the sample with B template above? Here is complete .cpp file https://gist.github.com/mloskot/5846468 Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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install with b2 - conflicting documentation
by Kirk Joppy 23 Jun '13

23 Jun '13

Hello, I am trying to build the regex library which I will then use through MinGW. I already installed MinGW and added ..\MinGW\bin to my system PATH. I now want to build regex and put it somewhere. I am aware of two different pieces of documentation detailing how to do this: http://www.boost.org/doc/libs/1_53_0/more/getting_started/windows.html#prep… http://www.boost.org/doc/libs/1_53_0/doc/html/bbv2/installation.html The main difference seems to be whether you should be in BOOST_ROOT or BOOST_ROOT\tools\build\v2. Which is it? In either case I gather than I should do this $ bootstrap.bat gcc and in fact I've done that in both BOOST_ROOT and BOOST_ROOT\tools\build\v2 with apparent success. I just don't know what I'm supposed to do next. I tried running $ b2 --prefix=H:\boost-test --with-regex install from within BOOST_ROOT\tools\build\v2, and that put some stuff into H:\boost-text, but I couldn't find any actual library files. Before I screw around any more I thought I'd ask knowledgeable folks for the right way to do this. Thank you very much, kjoppy

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An example: how I learned to iterate through property trees (ptree)
by Cook, Rich 22 Jun '13

22 Jun '13

I just wanted to post a program I wrote that creates a boost::ptree, saves it to JSON, reads it back, then iterates through the tree and prints its nodes. #include <boost/property_tree/ptree.hpp> #include <boost/property_tree/json_parser.hpp> #include <string> #include <iostream> using namespace std; using boost::property_tree::ptree; string indent(int level) { string s; for (int i=0; i<level; i++) s += " "; return s; } void printTree (ptree &pt, int level) { if (pt.empty()) { cerr << "\""<< pt.data()<< "\""; } else { if (level) cerr << endl; cerr << indent(level) << "{" << endl; for (ptree::iterator pos = pt.begin(); pos != pt.end();) { cerr << indent(level+1) << "\"" << pos->first << "\": "; printTree(pos->second, level + 1); ++pos; if (pos != pt.end()) { cerr << ","; } cerr << endl; } cerr << indent(level) << " }"; } return; } int main(int, char*[]) { // first, make a json file: string tagfile = "testing2.pt"; ptree pt1; pt1.put("object1.type","ASCII"); pt1.put("object2.type","INT64"); pt1.put("object3.type","DOUBLE"); pt1.put("object1.value","one"); pt1.put("object2.value","2"); pt1.put("object3.value","3.0"); pt1.put("object4.type", "ASCII"); pt1.put("object4.value", "shallow"); pt1.put("object4.subobject1.type", "ASCII"); pt1.put("object4.subobject1.value", "deep child"); pt1.put("object4.subobject1.subsubobject.type", "ASCII"); pt1.put("object4.subobject1.subsubobject.value", "deep child"); pt1.put("object5.type", "ASCII"); pt1.put("object5.value", "shallow"); write_json(tagfile, pt1); ptree pt; bool success = true; //try { read_json(tagfile, pt); printTree(pt, 0); cerr << endl; return success; } PROGRAM OUTPUT: rcook@rzbeast (blockbuster): ./ptree { "object1": { "type": "ASCII", "value": "one" }, "object2": { "type": "INT64", "value": "2" }, "object3": { "type": "DOUBLE", "value": "3.0" }, "object4": { "type": "ASCII", "value": "shallow", "subobject1": { "type": "ASCII", "value": "deep child", "subsubobject": { "type": "ASCII", "value": "deep child" } } }, "object5": { "type": "ASCII", "value": "shallow" } } -- ✐Richard Cook ✇ Lawrence Livermore National Laboratory Bldg-453 Rm-4024, Mail Stop L-557 7000 East Avenue, Livermore, CA, 94550, USA ☎ (office) (925) 423-9605 ☎ (fax) (925) 423-6961 --- Information Management & Graphics Grp., Services & Development Div., Integrated Computing & Communications Dept. (opinions expressed herein are mine and not those of LLNL)

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[smart_ptr] enable_shared_from_this and shared_ptr to a base class
by Adam Romanek 21 Jun '13

21 Jun '13

Hi, I have a question related to using shared_from_this() and a shared_ptr to a base class. Here's a modified version of the enable_shared_from_this usage example from its documentation web page: #include <boost/enable_shared_from_this.hpp> #include <boost/shared_ptr.hpp> #include <cassert> class X { public: virtual void foo() = 0; }; class Y: public X, public boost::enable_shared_from_this<Y> { virtual void foo() { shared_from_this(); } }; int main() { X* x_ptr = new Y; boost::shared_ptr<X> sp(x_ptr); sp->foo(); } First, class Y is now derived from class X. Secondly, shared_ptr's template argument is now X and the parameter to the shared_ptr's constructor is now a pointer to X. Now, calling shared_from_this() in X and/or Y throws boost::bad_weak_ptr. Is this correct behavior? Is it documented somewhere? I know that the example is a bit unrealistic since most of the time shared_ptr is constructed directly from the pointer returned by 'new Y' or created by make_shared() but still, this is something that bothers me. WBR, Adam Romanek

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Re: [Boost-users] [Test]: Problem with simple Boost.Test
by Damien Kick 21 Jun '13

21 Jun '13

On Jun 20, 2013, at 8:38 PM, <boost-users-request(a)lists.boost.org<mailto:boost-users-request@lists.boost.org>> wrote: Date: Thu, 20 Jun 2013 17:01:54 +0000 (UTC) From: Gennadiy Rozental <rogeeff(a)gmail.com<mailto:rogeeff@gmail.com>> To: boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> Subject: Re: [Boost-users] [Test]: Problem with simple Boost.Test Message-ID: <loom.20130620T185812-619(a)post.gmane.org<mailto:loom.20130620T185812-619@post.gmane.org>> Content-Type: text/plain; charset=utf-8 thusly:$ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma I know docs are not ideal but this part is very clear I thought. test_exec_monitor is an old alternative t ounit test framework, which is long deprecated and they definitely do not require each other In this case, I wouldn't fault the docs per se but rather only my impatience in having tried "jumping directly to the subject of [my] interest" but not yet having realized exactly what my subject of interest really is/was nor how far I needed to jump in order to get to it ;-) I had been trying this: $ cat cma.cpp #define BOOST_TEST_MODULE cma #include <boost/test/unit_test.hpp> #include <iostream> #include <ostream> BOOST_AUTO_TEST_CASE(sanity) { std::clog << "Test the world!\n"; } $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status $ But when I started reading through more of the documentation and got as far as <http://preview.tinyurl.com/lw7e688>, I realized that I needed to be doing something more like this: $ ${CXX} -c --std=c++0x -g -DBOOST_TEST_DYN_LINK -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma $ env DYLD_LIBRARY_PATH=${TARGET}/lib ./cma Running 1 test case... Test the world! *** No errors detected $ Thank you, Gennadiy, for having taken the time to respond to my question as well as having taken the time you spent on Boost.Test. ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

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Re: [Boost-users] [Test]: Problem with simple Boost.Test
by Damien Kick 21 Jun '13

21 Jun '13

Date: Mon, 17 Jun 2013 23:03:16 +0000 (UTC) From: legalize+jeeves(a)mail.xmission.com<mailto:legalize+jeeves@mail.xmission.com> (Richard) To: boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> Subject: Re: [Boost-users] [Test]: Problem with simple Boost.Test Message-ID: <kpo4jk$2ih$2(a)ger.gmane.org<mailto:kpo4jk$2ih$2@ger.gmane.org>> [Please do not mail me a copy of your followup] boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> spake the secret code <7364AB234369D348AE1CEBC1A86132DBAD32EA(a)SVLITMX02.shoretel.com<http://SVLITMX02.shoretel.com>> thusly: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Why are you linking against boost_test_exec_monitor? I've never needed to do that. boost_unit_test_framework should be enough. Interesting. Because I'm finding the following: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status $ But that is also what I'm finding with the system GCC and the Fink install of Boost 1.46, and so that behavior isn't unique my attempt to build/use a Boost with GCC 4.8.0 using --std=c++0x. $ g++ -c -g -I/sw/include cma.cpp -o cma.o $ g++ -g -L/sw/lib cma.o -lboost_unit_test_framework-mt Undefined symbols for architecture x86_64: "_main", referenced from: start in crt1.10.6.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status $ g++ --version i686-apple-darwin11-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) Copyright (C) 2007 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ fink list --tab boost1.46 Information about 7237 packages read in 1 seconds. i boost1.46.1.cmake 1.46.1-2 Boost C++ Libraries i boost1.46.1.cmake-shlibs 1.46.1-2 Boost C++ Libraries $ ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

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matrix inversion in boost.
by Mohit Singh 21 Jun '13

21 Jun '13

Hi, I am trying to do a simple matrix inversion operation using boost. But I am getting an error. Basically what I am trying to find is inversted_matrix = inverse(trans(matrix) * matrix) But I am getting an error Check failed in file boost_1_53_0/boost/numeric/ublas/lu.hpp at line 299: detail::expression_type_check (prod (triangular_adaptor<const_matrix_type, upper> (m), e), cm2) terminate called after throwing an instance of 'boost::numeric::ublas::internal_logic' what(): internal logic Aborted (core dumped) My attempt: #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/vector.hpp> #include <boost/numeric/ublas/io.hpp> #include <boost/numeric/ublas/vector_proxy.hpp> #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/triangular.hpp> #include <boost/numeric/ublas/lu.hpp> namespace ublas = boost::numeric::ublas; template<class T> bool InvertMatrix (const ublas::matrix<T>& input, ublas::matrix<T>& inverse) { using namespace boost::numeric::ublas; typedef permutation_matrix<std::size_t> pmatrix; // create a working copy of the input matrix<T> A(input); // create a permutation matrix for the LU-factorization pmatrix pm(A.size1()); // perform LU-factorization int res = lu_factorize(A,pm); if( res != 0 ) return false; // create identity matrix of "inverse" inverse.assign(ublas::identity_matrix<T>(A.size1())); // backsubstitute to get the inverse lu_substitute(A, pm, inverse); return true; } int main(){ using namespace boost::numeric::ublas; matrix<double> m(4,5); vector<double> v(4); vector<double> thetas; m(0,0) = 1; m(0,1) = 2104; m(0,2) = 5; m(0,3) = 1;m(0,4) = 45; m(1,0) = 1; m(1,1) = 1416; m(1,2) = 3; m(1,3) = 2;m(1,4) = 40; m(2,0) = 1; m(2,1) = 1534; m(2,2) = 3; m(2,3) = 2;m(2,4) = 30; m(3,0) = 1; m(3,1) = 852; m(3,2) = 2; m(3,3) = 1;m(3,4) = 36; std::cout<<m<<std::endl; matrix<double> product = prod(trans(m), m); std::cout<<product<<std::endl; matrix<double> inversion(5,5); bool inverted; inverted = InvertMatrix(product, inversion); std::cout<<inversion<<std::endl; } -- Mohit "When you want success as badly as you want the air, then you will get it. There is no other secret of success." -Socrates

1 0

[BGL] boykov_kolbogorov_max_flow() classes / groups
by Nil Goyette 20 Jun '13

20 Jun '13

I have been testing the the boykov_kolbogorov_max_flow function in the previous weeks and I have a question that I can't seem to find the answer myself. I asked for it on StackOverflow [1] but nobody answered. Can someone tell me why I get three classes (groups) instead of two? I always get class '0' and '4', and '1' on some cases. I thought a Graph Cut was supposed to output only two classes, so what's the meaning of '1'? Please read the SO question in [1] for more details. Thanks for your time. Nil Goyette [1] http://stackoverflow.com/questions/16905613/3-classes-0-1-4-on-boost-graph-…

1 0

accumulator extended quantil value
by Philipp Kraus 20 Jun '13

20 Jun '13

Hello, I have got created an extended_p_square_quantile into an accumulator, with 3 quantils (0.25, 0.5, 0.75) as a boost::array. How can I get access to the quantil values of the accumulator? For the variance I use accumulator::variance(myacc), but a call with quantil(myacc, 0.5) does not work. Thanks Phil

2 3

boost_1_53_0: no matching function for call to ‘hash_value
by Shailja Kumari 20 Jun '13

20 Jun '13

> Hi , > > I am using boost_1_53_0 for my applications build. The boost_1_53_0 is > throwing the following error message. > > boost_1_53_0/boost/functional/hash/extensions.hpp:269:34: error: no > matching function for call to ‘hash_value(const > Rubedo::Utils::Hashing::HashedString<16>&)’ > return hash_value(val); > ^ > > boost_1_53_0/boost/functional/hash/hash.hpp:187:57: error: no type named > ‘type’ in ‘struct > boost::hash_detail::basic_numbers<Rubedo::Utils::Hashing::HashedString<16> > >’ > > The following code build fine with boost_1_49_0, but have error with > boost_1_53_0 on linux. Do you have fixes for these ? Please let me know. > > Thanks > >

2 1

boost serialisation, PORTABLE_BINARY_ARCHIVE fix required
by avib369 . 20 Jun '13

20 Jun '13

Currently portable binary archive is broken on AIX platforms. The reason is because the default 'char' type is unsigned on this platform. Whereas for most other platforms it is signed, By going through the portable binary and replacing 'char' with 'signed char' this long standing bug is fixed. I have tested the fix on Linux(opensuse103,opensuse113, HPUX, AIX(power6,power7) This is a fairly safe and quick fix, can I please ask the authors of this library to add this fix, for the next version of boost. Here are the changes I made: (flagged under ' // changed ' comment //-------------------------------------------------------- portable_binary_iarchive.hpp void load(signed char & t){ // changed this->primitive_base_t::load(t); } //------------------------------------------------------------- portable_binary_iarchive.cpp void portable_binary_iarchive::load_impl(boost::intmax_t & l, char maxsize){ signed char size; // changed l = 0; this->primitive_base_t::load(size); if(0 == size){ return; } bool negative = (size < 0); ...... // ----------------------------------------------------------------- portable_binary_oarchive.hpp void save(const signed char & t){ // changed this->primitive_base_t::save(t); } // ----------------------------------------------------------- portable_binary_oarchive.cpp void portable_binary_oarchive::save_impl( const boost::intmax_t l, const char maxsize ){ signed char size = 0; // changed if(l == 0){ this->primitive_base_t::save(size); return; } .......... // ------------------------------ Ta, Avi

2 1

[property_tree] Population and Json formatting
by Michael Powell 20 Jun '13

20 Jun '13

Hello, Question about property tree. I've got an "event" concept which I want to serialize to Json through property tree. If I go something like this: ptree tree; tree.set<int>("event.id", 1); Then the resulting Json would look something like this? { "event": { "id": 1 } } or possibly? { "event": { "id" : "1" } } or possibly, with pretty turned off (nicer for message framing). {"event":{"id":"1"}} Thank you... Regards, Michael Powell

1 0

Boost and Norton 360
by Scott Alexander 20 Jun '13

20 Jun '13

Hi, I have just installed boost 1.53 32bit using the Sourceforge Visual Studio installer and my security software (Norton 360) has quarantined three files as being high risk: *boost_math_tr1f-vc110-mt-1_53.dll *boost_thread-vc110-mt-gd-1_53.dll *boost_filesystem-vc110-mt-gd-1_53.dll Does anyone know if this is common? Can I safely restore these files? Thanks, Scott

3 2

errors in boost build - 1.5.3 on Linux Mint 15 (Olivia) 64-bit
by asif saeed 20 Jun '13

20 Jun '13

Hi, I am trying to build boost 1.53 using GCC and have got the following errors: ...failed updating 348 targets... ...skipped 72 targets... ...updated 4568 targets... The "failed updating 348 targets..." shows that something has definitely gone wrong. Can any kind soul tell me what has happened? I used the following command after bootstrap: ./b2 --prefix=./ --build-type=complete --stagedir=./stage --layout=versioned --toolset=gcc Help me please. -Best regards, -Asif

2 1

[program_options] Custom Validation for a String Value
by Ryan 19 Jun '13

19 Jun '13

Hello, Is there a way of validating a string type program option before it's stored in the map? add_options() ("arg" , value<std::string>()->default_value("Hi"), "Greeting"); boost::regex pattern("^(Hello | Good Morning | Hi)$"); I've used custom validation for types that program options doesn't recognize. I'd like to check the string before it's stored in the map like the custom validation does for unknown types. I'd rather the error be caught early. Is there a way to use the regex against the program option? Ryan

1 0

Mutex synchronised wrapper class for boost::interprocess shared memory vector of strings
by Riskybiz 19 Jun '13

19 Jun '13

I'm trying to write a wrapper class in C++ to give mutex synchronised interprocess access to a shared memory vector of strings. This is my first foray into boost::interprocess and allocators are proving something of a mystery. Is anyone able to see why on compilation I get the error: error C2512: 'boost::interprocess::allocator::allocator' : no appropriate default constructor available C:\Program Files (x86)\Boost\boost_1_53_0\boost\container\string.hpp #ifndef SHARED_MEMORY_WRAPPER_H//if not defined already #define SHARED_MEMORY_WRAPPER_H//then define it #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <boost/interprocess/sync/named_mutex.hpp> using namespace boost::interprocess; class SharedMemoryWrapper { public: SharedMemoryWrapper(const std::string &name, bool server) : m_name(name), m_server(server) { if (server) { named_mutex::remove("named_mutex"); shared_memory_object::remove(m_name.c_str()); //Create shared memory managed_shared_memory m_segment(create_only, m_name.c_str(), 10000); //Create allocators CharAllocator charallocator(m_segment.get_segment_manager()); StringAllocator stringallocator(m_segment.get_segment_manager()); //This string is in only in this process (the pointer pointing to the //buffer that will hold the text is not in shared memory). //But the buffer that will hold "this is my text" is allocated from //shared memory MyShmString mystring(charallocator); mystring = "this is my text"; //This vector is fully constructed in shared memory. All pointers //buffers are constructed in the same shared memory segment //This vector can be safely accessed from other processes. MyShmStringVector *sharedSegmentVector = m_segment.construct<MyShmStringVector>("sharedSegmentVector")(stringallocato r); sharedSegmentVector->push_back(mystring); } else { //Open the shared segment managed_shared_memory m_segment(open_only, name.c_str()); //Find the vector using the c-string name and open it MyShmStringVector *sharedSegmentVector = m_segment.find<MyShmStringVector>("sharedSegmentVector").first; } m_mutex = new named_mutex(open_or_create, "named_mutex"); } ~SharedMemoryWrapper() { if (m_server) { named_mutex::remove("named_mutex"); //Destroy the vector from the managed_shared_memory m_segment->destroy_ptr(sharedSegmentVector);//This will free all strings that the vector contains m_segment->destroy<MyShmStringVector>("sharedSegmentVector");//Destroy the vector //Is it necessary to destroy the allocators here? //Remove the managed_shared_memory; this may fail if the memory does not exist or is mapped or opened by another process shared_memory_object::remove(m_name.c_str()); } delete m_mutex; delete m_segment; } //Writer void push(const std::string & in) { scoped_lock<named_mutex> lock(*m_mutex); MyShmString inStr = in.c_str(); sharedSegmentVector->push_back(inStr); } //Reader function yet to be coded. Needs to return a vector containing a subset range of elements from the shared-memory-vector. private: //Typedefs typedef boost::interprocess::allocator<char, managed_shared_memory::segment_manager> CharAllocator; typedef boost::interprocess::basic_string<char, std::char_traits<char>, CharAllocator> MyShmString; typedef boost::interprocess::allocator<MyShmString, managed_shared_memory::segment_manager> StringAllocator; typedef boost::interprocess::vector<MyShmString, StringAllocator> MyShmStringVector; bool m_server; std::string m_name; managed_shared_memory *m_segment; MyShmStringVector *sharedSegmentVector; named_mutex *m_mutex; };//class #endif//header guard With thanks, Riskybiz

2 1

[statechart] [spirit] OSI delimited message framing
by Michael Powell 19 Jun '13

19 Jun '13

Hello, I need to design a delimited message framing for TCP/IP sockets, probably using Asio to facilitate transport. Then build an OSI layer 7 application vernier to handle framing. I've dabbled a bit with Spirit and cooked up a couple of "simple" micro grammars throughout the code base. In a sense, I could see a delimited message framing strategy being a grammar of sorts, but this seems somewhat complex for a grammar to handle when you consider the overhead of verifying pass/fail (message or not a message), plus extracting the message within the delimiters. Or, more likely approach the problem with statechart in mind. I've dealt with framed messages in the past more like this. One state is the escape byte, which can be followed by SOM, EOM, or another true-escape-byte (intended message byte). Plus other fields like message type, sub-type, how to handle payload, arguments, and so forth. Anyone else dealt with things like this before? With Spirit? With Statechart? Regards, Michael Powell

5 5

Re: [Boost-users] Boost-users Digest, Vol 3479, Issue 1
by Damien Kick 19 Jun '13

19 Jun '13

Date: Mon, 17 Jun 2013 23:03:16 +0000 (UTC) From: legalize+jeeves(a)mail.xmission.com<mailto:legalize+jeeves@mail.xmission.com> (Richard) To: boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> Subject: Re: [Boost-users] [Test]: Problem with simple Boost.Test Message-ID: <kpo4jk$2ih$2(a)ger.gmane.org<mailto:kpo4jk$2ih$2@ger.gmane.org>> [Please do not mail me a copy of your followup] boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org> spake the secret code <7364AB234369D348AE1CEBC1A86132DBAD32EA(a)SVLITMX02.shoretel.com<http://SVLITMX02.shoretel.com>> thusly: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Why are you linking against boost_test_exec_monitor? I've never needed to do that. boost_unit_test_framework should be enough. Interesting. Because I'm finding the following: $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma Undefined symbols for architecture x86_64: "_main", referenced from: implicit entry/start for main executable ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status $ But that is also what I'm finding with the system GCC and the Fink install of Boost 1.46, and so that behavior isn't unique my attempt to build/use a Boost with GCC 4.8.0 using --std=c++0x. $ g++ -c -g -I/sw/include cma.cpp -o cma.o $ g++ -g -L/sw/lib cma.o -lboost_unit_test_framework-mt Undefined symbols for architecture x86_64: "_main", referenced from: start in crt1.10.6.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status $ g++ --version i686-apple-darwin11-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) Copyright (C) 2007 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. $ fink list --tab boost1.46 Information about 7237 packages read in 1 seconds. i boost1.46.1.cmake 1.46.1-2 Boost C++ Libraries i boost1.46.1.cmake-shlibs 1.46.1-2 Boost C++ Libraries $ ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

1 0

[asio] Serial and TCP I/O
by Michael Powell 19 Jun '13

19 Jun '13

Hello, I have an application that I'd like to leverage some common code if at all possible (and/or necessary), using concepts of client/server, reader/writer, and so on. Probably also TCP/IP and/or Serial, although I gather Asio has a serial class ready to go out of the box? Serial is pretty much a "no brainer", can be a server, but to talk to devices in our use case, always the client, can be either reader or writer or both. The key question here is, do we need a separate io_service for serial as well as for TCP? Regards, Michael Powell

2 1

What is the status of the BGL-Python Bindings project
by lizy10b 19 Jun '13

19 Jun '13

Hi there, I would like to know what is the status of the BGL-Python Bindings project? The Boost 1.53 document says that "The Python bindings for the BGL are now part of a separate project" and links to http://www.osl.iu.edu/~dgregor/bgl-python/ On that page I find that the latest version is 0.9 which was released in 2005. So it means the BGL-Python Binding project is not on going? Is the BGL-Python Bindings 0.9 compatible to Boost 1.53 ? Or any other ways to use Boost graph functionalities in python? Thanks Zhiyu Li 2013-06-19 lizy10b

3 7

[build] Problem building using Intel C++ compiler
by Jason 19 Jun '13

19 Jun '13

I'm trying to build v1.53 using the Intel C++ compiler and am having some problems. I'm issuing the following commands: ./bootstrap.sh --with-toolset=intel-linux ./b2 toolset=intel-linux Upon executing the second command, I get the following error: error: intel-linux initialization: parameter 'version' inconsistent error: no value was specified in earlier initialization error: an explicit value is specified now This appears to be similar to a mailing list thread regarding v1.39, archived here: https://groups.google.com/forum/#!topic/boost-list/gu9wf3cr15Y It appears that there is a workaround listed there (and a corresponding Trac ticket #3165) that involves hand-manipulation of bjam configuration files, but it seems like this is something that should work out of the box if Intel C++ is a supported toolset. Is there any chance that this would be fixed in the future? Jason -- View this message in context: http://boost.2283326.n4.nabble.com/build-Problem-building-using-Intel-C-com… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

[BGL] null_vertex()
by Andreas Fabri 18 Jun '13

18 Jun '13

Hello, I am wondering what the function boost::graph_traits<G>::null_vertex() http://www.boost.org/doc/libs/1_53_0/libs/graph/doc/Graph.html is for, and why there is no equivalent function null_edge() best regards, andreas -- Andreas Fabri, PhD Chief Officer, GeometryFactory Editor, The CGAL Project phone: +33.492.954.912 skype: andreas.fabri

2 2

[Test]: Problem with simple Boost.Test
by Damien Kick 17 Jun '13

17 Jun '13

I'm trying to get what I think should be a simple example of Boost.Test (Boost 1.53) to work but I'm getting a segmentation fault, having used other of the Boost libraries from the same build/install of 1.53 without any problems. Am I doing anything obviously wrong? Thanks in advance for any help. $ cat test/cma.cpp #define BOOST_TEST_MODULE cma #include <boost/test/unit_test.hpp> #include <iostream> #include <ostream> BOOST_AUTO_TEST_CASE(sanity) { std::clog << "Test the world!\n"; } $ make check [100%] Building CXX object CMakeFiles/test-cma.dir/test/cma.cpp.o Linking CXX executable test-cma [100%] Built target test-cma [100%] Built target check $ env DYLD_LIBRARY_PATH=${TARGET}/lib ./test-cma Running 1 test case... Test the world! Segmentation fault: 11 $ Here are some more details. I'm trying this on Mac with GCC. $ uname -a Darwin Damien-Kicks-MacBook-Pro.local 12.4.0 Darwin Kernel Version 12.4.0: \ Wed May 1 17:57:12 PDT 2013; root:xnu-2050.24.15~1/RELEASE_X86_64 x86_64 $ ${CXX} --version g++ (GCC) 4.8.0 Copyright (C) 2013 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. I've compiled my build/install of Boost 1.53 with --std=c++0x. Again, I've used other libraries from this same build/install (DateTime, Filesystem, Random, Regex, Serialization, System, Thread), so I don't think that the problem is my use of --std=c++0x in and of itself. $ ${CXX} -c --std=c++0x -g -I${TARGET}/include cma.cpp -o cma.o $ ${CXX} --std=c++0x -g cma.o ${TARGET}/lib/libboost_test_exec_monitor.a \ ${TARGET}/lib/libboost_unit_test_framework.dylib -o cma $ env DYLD_LIBRARY_PATH=${TARGET}/lib ./cma Running 1 test case... Test the world! Segmentation fault: 11 $ If I run this under GDB (gdb) run Starting program: cma Reading symbols for shared libraries ++++.............................. done Running 1 test case... Test the world! Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000 boost::unit_test::framework::get (id=65536, t=tut_case) at \ impl/framework.ipp:388 388 if( (res->p_type & t) == 0 ) (gdb) bt #0 boost::unit_test::framework::get (id=65536, t=tut_case) at \ impl/framework.ipp:388 #1 0x0000000100134805 in boost::unit_test::traverse_test_tree \ (suite=@0x100403f10, V=@0x7fff5fbff470) at framework.hpp:73 Previous frame inner to this frame (gdb could not unwind past this frame) (gdb) print res $1 = ('boost::unit_test::test_unit' *) 0x0 (gdb) ________________________________ This e-mail and any attachments are confidential. If it is not intended for you, please notify the sender, and please erase and ignore the contents.

2 1

[filesystem] Create file with a unicode filename/path
by Konstantin Kronfeldner 17 Jun '13

17 Jun '13

Hello, I'm working under windows 7 with mingw. I have encountered some weird behaviour with unicode filenames. My program needs to be portable, and I'm using boost::filesystem (v 1.53) to handle the file paths. This has all been going well, until I needed to open files with unicode filenames. This is not about the content of the file, but the file's name/path. I tried the following: For testing I made a folder named C:\UnicodeTest\|????????|and I tried creating a file inside of it, by appending the file name test.txt to the boost wpath. For some reason the creation of the file fails. I'm using boost's fstreams and when I try to open the file, the failbit of the stream is set. Now the funny thing is, that when I append a foldername to the path instead, a call to create_directories() succeeds and creates the correct directory C:\UnicodeTest\|????????|\folder. I really don't understand why it won't work with a file. I have also posted my problem on stackoverflow. http://stackoverflow.com/questions/16875025/open-a-file-with-unicode-path No luck so far. This is the code I use: boost::filesystem::wpath path; // find the folder to test (There are no other folders in C:\UnicodeTest) boost::filesystem::wpath dirPath = "C:\\UnicodeTest"; vector<boost::filesystem::wpath> files; copy(boost::filesystem::directory_iterator(dirPath), boost::filesystem::directory_iterator(), back_inserter(files)); for(boost::filesystem::wpath &file : files) { if(boost::filesystem::is_directory(file)) { path = file; break; } } // create a path for the folder boost::filesystem::wpath folderPath = path / "folder"; // this works just fine boost::filesystem::create_directories(folderPath); // create a path for the file boost::filesystem::wpath filePath = path / "test.txt"; boost::filesystem::ofstream stream; // this fails stream.open(filePath); if(!stream) { cout << "failed to open file " << path << endl; } else { cout << "success" << endl; }

1 0

Comparison boost spirit and ANTLR
by Olivier Austina 17 Jun '13

17 Jun '13

Hi, I would like to choose a parser. I would like to use a parser for text processing (natural language text). Which parser is suited in this case. In general which are the benefit to use boost spirit instead of ANTLR or ANTLR instead of boost spirit. Thank you. -- Regards Austina

9 15

[statechart] state_machine send_event assertion fails
by Gooding, Dustin R. (JSC-ER411) 17 Jun '13

17 Jun '13

Hello, I'm a new user of statechart and for the most part am enjoying it very much. I've implemented a state machine with about 30 states (9 orthogonal regions) and over 50 events. It works very well and as expected, except for this one issue. Every once in a while, and in a way I've been unable to consistently repeat, I get an assertion failure resulting in a core dump. /usr/include/boost/statechart/state_machine.hpp:873: boost::statechart::detail::reaction_result boost::statechart::state_machine<MostDerived, InitialState, Allocator, ExceptionTranslator>::send_event(const event_base_type&) [with MostDerived = GripperPosition, InitialState = Container, Allocator = std::allocator<void>, ExceptionTranslator = boost::statechart::null_exception_translator, boost::statechart::state_machine<MostDerived, InitialState, Allocator, ExceptionTranslator>::event_base_type = boost::statechart::event_base]: Assertion `get_pointer( pOutermostUnstableState_ ) == 0' failed. "GripperPosition" is my state_machine. "Container" is the simple_state the state machine initially enters. Container has no transitions, but many sub states (it's the owner of the 9 orthogonal regions). (As far as I can tell, if the state machine is alive, then "Container" is an active state.) "Container" has a handful of custom_reactions that essentially listen for user-supplied events, "forward" those events in to the appropriate orthogonal regions using internal-only events, and then discard the user-supplied events. The intention here is to have a single event propagate to multiple orthogonal regions, allowing them all to react. For example: boost::statechart::result Container::react(const e_still&) { post_event(i_still_action()); post_event(i_still_moving()); return discard_event(); } I am unsure if these reactions are the cause of the assertion failure, but given that the error message says "Container" is the InitialState, I have to assume so. Given that, I don't see how either Container or GripperPosition are inactive and don't know how to interpret this error. I'd appreciate some guidance. I'm running Ubuntu 12.04, GCC 4.6.3, and Boost 1.46.1. -- Dustin Gooding NASA/JSC Robotics

4 7

[multiprecision] noexcept() usage in gmp int
by Francesco Biscani 16 Jun '13

16 Jun '13

Hello, I was trying out the new multiprecision library (kudos!), and I ran into a problem. In order to make certain guarantees in my code regarding exception safety, I am mandating that types being used in generic containers are marked noexcept() for certain basic operations (namely, destruction and move operations). It seems like this is generally guaranteed in the multiprecision library (tried with cpp_int and the mpfr adaptor), with the important exception of the gmp integer class. A glance at the headers reveals that (gmp.hpp): // // Within this file, the only functions we mark as noexcept are those that manipulate // (but don't create) an mpf_t. All other types may allocate at pretty much any time // via a user-supplied allocator, and therefore throw. // Additionally, browsing the gmp documentation yields this snippet ( http://gmplib.org/manual/Custom-Allocation.html) """ There's currently no defined way for the allocation functions to recover from an error such as out of memory, they must terminate program execution. A longjmp or throwing a C++ exception will have undefined results. This may change in the future. """ Would it be possible then for the mp library authors to consider adding basic noexcept() guarantees to the gmp adaptor class in future versions? Cheers and thanks for the great library, Francesco.

2 2

Building a large graph using Parallel Boost Graph Library
by William Shipman 15 Jun '13

15 Jun '13

Hi all, I'm working with a graph that has about 16 million vertices and 320 million edges. Currently, I'm using graph-tool in Python but building the graph is far too slow. Before I start porting to C++ I starting reading up on the Parallel Boost Graph Library. From the examples in the documentation, it seems that one must build the graph on one node in the cluster, then call synchronize to send that graph to all nodes. Is there a way to build parts of the graph on each node and then synchronize those parts? Some background: the graph actually comes from a CT scan. The vertices are voxels, the edges are relationships between adjacent voxels. At the moment I'm working on a very small test volume - 256^3 voxels - but later volumes will have billions of vertices and edges. Thanks for the help.

1 0

Regarding boost interval library package.
by Pranjal vyas 15 Jun '13

15 Jun '13

Hello, I have written a program in boost which simply calculates the exponent in an interval, but for some interval inputs it is giving the wrong output such as for [1,3] or [-1,3]...but for some values it is giving correct o/p such as [1,9]. Please help in solving this query. The program is appended below.... ********************************************************************************************************************************************************* #include </boost/numeric/interval.hpp> #include <vector> #include <algorithm> #include <utility> #include <iostream> #include <iomanip> #include <math.h> using namespace boost; using namespace numeric; using namespace interval_lib; template<class T, class Policies> std::ostream &operator<<(std::ostream &os, const boost::numeric::interval<T, Policies> &x) { os << "[" << x.lower() << ", " << x.upper() << "]"; return os; } int main() { typedef interval<double,policies<save_state<rounded_transc_opp<double> >,checking_base<double> > > I; //typedef interval<double> I; I a(1,3.2); std::cout << exp(a) << std::endl; } ********************************************************************************************************************************************************** Thanks in Advance. Regards, PV

1 0

http://www.boost.org/doc/libs/1_53_0/libs/serialization/example/demo.cpp does not work properly when using polymorphic xml archive
by Fadhel 14 Jun '13

14 Jun '13

Hi all, I used http://www.boost.org/doc/libs/1_53_0/libs/serialization/example/demo.cpp file as a first introduction to boost serialization. I would like to use polymorphic archives with XML serilialization format (to avoid having the templatized version). I edited this example and run it. Writing the data has worked fine -- except for the base_class serialization which needed an nvp -- but reading it causes a memory/segmentation fault problem. The same error happens with a binary archive. Using a text archive works fine. I'm new to boost serialization and debugging the code did not help me a lot. Is there anything specific to the serialization of base classes or abstract classes with the polymorphic XML format which needs to be handled? Or is this related to the serialization of pointers to the base class. Thanks for your help. Best Regards, Fadhel BA Here is the code I'm using: ( I removed some comments to make the code shorter) /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 // demo.cpp #include <cstddef> // NULL #include <iomanip> #include <iostream> #include <fstream> #include <string> #include <boost/archive/polymorphic_iarchive.hpp> #include <boost/archive/polymorphic_oarchive.hpp> #include <boost/archive/polymorphic_xml_iarchive.hpp> #include <boost/archive/polymorphic_xml_oarchive.hpp> #include <boost/archive/polymorphic_binary_iarchive.hpp> #include <boost/archive/polymorphic_binary_oarchive.hpp> #include <boost/archive/polymorphic_text_iarchive.hpp> #include <boost/archive/polymorphic_text_oarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/assume_abstract.hpp> #include <boost/serialization/nvp.hpp> ///////////////////////////////////////////////////////////// // gps coordinate // // llustrates serialization for a simple type // class gps_position { friend std::ostream & operator<<(std::ostream &os, const gps_position &gp); friend class boost::serialization::access; int degrees; int minutes; float seconds; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int /* file_version */) const { ar << BOOST_SERIALIZATION_NVP(degrees); ar << BOOST_SERIALIZATION_NVP(minutes); ar << BOOST_SERIALIZATION_NVP(seconds); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int /* file_version */) { ar >> BOOST_SERIALIZATION_NVP(degrees); ar >> BOOST_SERIALIZATION_NVP(minutes); ar >> BOOST_SERIALIZATION_NVP(seconds); } public: // every serializable class needs a constructor gps_position(){}; gps_position(int _d, int _m, float _s) : degrees(_d), minutes(_m), seconds(_s) {} }; std::ostream & operator<<(std::ostream &os, const gps_position &gp) { return os << ' ' << gp.degrees << (unsigned char)186 << gp.minutes << '\'' << gp.seconds << '"'; } ///////////////////////////////////////////////////////////// // One bus stop // // illustrates serialization of serializable members // class bus_stop { friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_stop &gp); virtual std::string description() const = 0; gps_position latitude; gps_position longitude; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << BOOST_SERIALIZATION_NVP(latitude); ar << BOOST_SERIALIZATION_NVP(longitude); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> BOOST_SERIALIZATION_NVP(latitude); ar >> BOOST_SERIALIZATION_NVP(longitude); } protected: bus_stop(const gps_position & _lat, const gps_position & _long) : latitude(_lat), longitude(_long) {} public: bus_stop(){} virtual ~bus_stop(){} }; BOOST_SERIALIZATION_ASSUME_ABSTRACT(bus_stop) std::ostream & operator<<(std::ostream &os, const bus_stop &bs) { return os << bs.latitude << bs.longitude << ' ' << bs.description(); } ///////////////////////////////////////////////////////////// // Several kinds of bus stops // // illustrates serialization of derived types // class bus_stop_corner : public bus_stop { friend class boost::serialization::access; std::string street1; std::string street2; virtual std::string description() const { return street1 + " and " + street2; } void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { // save/load base class information ar << boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar << BOOST_SERIALIZATION_NVP(street1); ar << BOOST_SERIALIZATION_NVP(street2);; } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { // save/load base class information ar >> boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar >> BOOST_SERIALIZATION_NVP(street1); ar >> BOOST_SERIALIZATION_NVP(street2); } public: bus_stop_corner(){} bus_stop_corner(const gps_position & _lat, const gps_position & _long, const std::string & _s1, const std::string & _s2 ) : bus_stop(_lat, _long), street1(_s1), street2(_s2) { } }; class bus_stop_destination : public bus_stop { friend class boost::serialization::access; std::string name; virtual std::string description() const { return name; } void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar << BOOST_SERIALIZATION_NVP(name); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar >> BOOST_SERIALIZATION_NVP(name); } public: bus_stop_destination(){} bus_stop_destination( const gps_position & _lat, const gps_position & _long, const std::string & _name ) : bus_stop(_lat, _long), name(_name) { } }; ///////////////////////////////////////////////////////////// // a bus route is a collection of bus stops // // illustrates serialization of STL collection templates. // // illustrates serialzation of polymorphic pointer (bus stop *); // class bus_route { friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_route &br); typedef bus_stop * bus_stop_pointer; std::list<bus_stop_pointer> stops; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { // in this program, these classes are never serialized directly but rather // through a pointer to the base class bus_stop. So we need a way to be // sure that the archive contains information about these derived classes. //ar.template register_type<bus_stop_corner>(); ar.register_type(static_cast<bus_stop_corner *>(NULL)); //ar.template register_type<bus_stop_destination>(); ar.register_type(static_cast<bus_stop_destination *>(NULL)); // serialization of stl collections is already defined // in the header ar << BOOST_SERIALIZATION_NVP(stops); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar.register_type(static_cast<bus_stop_corner *>(NULL)); ar.register_type(static_cast<bus_stop_destination *>(NULL)); // in the header ar >> BOOST_SERIALIZATION_NVP(stops); } public: bus_route(){} void append(bus_stop *_bs) { stops.insert(stops.end(), _bs); } }; std::ostream & operator<<(std::ostream &os, const bus_route &br) { std::list<bus_stop *>::const_iterator it; // note: we're displaying the pointer to permit verification // that duplicated pointers are properly restored. for(it = br.stops.begin(); it != br.stops.end(); it++){ os << '\n' << std::hex << "0x" << *it << std::dec << ' ' << **it; } return os; } ///////////////////////////////////////////////////////////// // a bus schedule is a collection of routes each with a starting time class bus_schedule { public: // note: this structure was made public. because the friend declarations // didn't seem to work as expected. struct trip_info { void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int file_version) const { // in versions 2 or later if(file_version >= 2) // read the drivers name ar << BOOST_SERIALIZATION_NVP(driver); // all versions have the follwing info ar << BOOST_SERIALIZATION_NVP(hour); ar << BOOST_SERIALIZATION_NVP(minute); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int file_version) { // in versions 2 or later if(file_version >= 2) // read the drivers name ar >> BOOST_SERIALIZATION_NVP(driver); // all versions have the follwing info ar >> BOOST_SERIALIZATION_NVP(hour); ar >> BOOST_SERIALIZATION_NVP(minute); } // starting time int hour; int minute; // only after system shipped was the driver's name added to the class std::string driver; trip_info(){} trip_info(int _h, int _m, const std::string &_d) : hour(_h), minute(_m), driver(_d) {} }; private: friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_schedule &bs); friend std::ostream & operator<<(std::ostream &os, const bus_schedule::trip_info &ti); std::list<std::pair<trip_info, bus_route *> > schedule; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << BOOST_SERIALIZATION_NVP(schedule); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> BOOST_SERIALIZATION_NVP(schedule); } public: void append(const std::string &_d, int _h, int _m, bus_route *_br) { schedule.insert(schedule.end(), std::make_pair(trip_info(_h, _m, _d), _br)); } bus_schedule(){} }; BOOST_CLASS_VERSION(bus_schedule, 2) std::ostream & operator<<(std::ostream &os, const bus_schedule::trip_info &ti) { return os << '\n' << ti.hour << ':' << ti.minute << ' ' << ti.driver << ' '; } std::ostream & operator<<(std::ostream &os, const bus_schedule &bs) { std::list<std::pair<bus_schedule::trip_info, bus_route *> >::const_iterator it; for(it = bs.schedule.begin(); it != bs.schedule.end(); it++){ os << it->first << *(it->second); } return os; } void save_schedule(const bus_schedule &s, const char * filename){ // make an archive std::ofstream ofs(filename); boost::archive::polymorphic_xml_oarchive oa(ofs); oa << s; } void restore_schedule(bus_schedule &s, const char * filename) { // open the archive std::ifstream ifs(filename); boost::archive::polymorphic_xml_iarchive ia(ifs); // restore the schedule from the archive ia >> s; } int main(int argc, char *argv[]) { // make the schedule bus_schedule original_schedule; // fill in the data // make a few stops bus_stop *bs0 = new bus_stop_corner( gps_position(34, 135, 52.560f), gps_position(134, 22, 78.30f), "24th Street", "10th Avenue" ); bus_stop *bs1 = new bus_stop_corner( gps_position(35, 137, 23.456f), gps_position(133, 35, 54.12f), "State street", "Cathedral Vista Lane" ); bus_stop *bs2 = new bus_stop_destination( gps_position(35, 136, 15.456f), gps_position(133, 32, 15.300f), "White House" ); bus_stop *bs3 = new bus_stop_destination( gps_position(35, 134, 48.789f), gps_position(133, 32, 16.230f), "Lincoln Memorial" ); // make a routes bus_route route0; route0.append(bs0); route0.append(bs1); route0.append(bs2); // add trips to schedule original_schedule.append("bob", 6, 24, &route0); original_schedule.append("bob", 9, 57, &route0); original_schedule.append("alice", 11, 02, &route0); // make aother routes bus_route route1; route1.append(bs3); route1.append(bs2); route1.append(bs1); // add trips to schedule original_schedule.append("ted", 7, 17, &route1); original_schedule.append("ted", 9, 38, &route1); original_schedule.append("alice", 11, 47, &route1); // display the complete schedule std::cout << "original schedule"; std::cout << original_schedule; std::string filename("C:/Dev/XML"); filename += "/demofile.xml"; // save the schedule save_schedule(original_schedule, filename.c_str()); // ... some time later // make a new schedule bus_schedule new_schedule; std::cout << "\n\nstarting restored schedule"; restore_schedule(new_schedule, filename.c_str()); // and display std::cout << "\nrestored schedule"; std::cout << new_schedule; // should be the same as the old one. (except for the pointer values) delete bs0; delete bs1; delete bs2; delete bs3; return 0; }

2 1

Boost 32-64
by Dave Dyer 14 Jun '13

14 Jun '13

This is sort of a final report to thank the list for several good pieces of advice. I'm just completing a project which uses boost libraries to assist a project which uses shared memory to communicate between a 64 bit process and a separate 32 bit Application. Trying to use the managed version of shared memory proved to be too unreliable. Doing so is advertized as "experimental" and it proved not ready for prime time. I succeeded by using only the very simplest, unmanaged versions of boost shared memory and managing my own memory, very carefully, to be sure the shared structures were identical on the 32 and 64 bit sides of the divide.

1 0

[unordered] order in container
by gast128 14 Jun '13

14 Jun '13

Hello all, although it's called 'unordered_set', it surprised me that an unordered container could have a different ordering although its contents are the same: void f() { boost::unordered_set<int> uset1; uset1.insert(10); uset1.insert(9); uset1.insert(8); boost::unordered_set<int> uset2; uset2.insert(8); uset2.insert(9); uset2.insert(10); //uset1: 8, 9, 10 //uset2: 10, 9, 8 bool b = uset1 == uset2; //ok, they are the same } Maybe it is somewhere in the documentation, otherwise maybe add a documentation note.

3 2

[accumulator] compiler error with quantil
by Philipp Kraus 14 Jun '13

14 Jun '13

Hello, I try to create a complex accumulator. I would like to use an accumulator for a box plot with the whisker data ( http://en.wikipedia.org/wiki/Box_plot ). My typedef shows at the momen like this: typedef boost::accumulators::accumulator_set<double, boost::accumulators::stats< boost::accumulators::tag::count, boost::accumulators::tag::sum, //boost::accumulators::tag::median, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square > > Accumulator; I would like to create the 25% & 75% quantil and replace the median with the 50% quantil, so I have defined the ctor accumulator call like this: boost::array<double, 3> probs = {0.25, 0.5, 0.75}; m_times[p_name] = Accumulator( boost::accumulators::extended_p_square_probabilities = probs ); (the median is disabled and m_times is a std::map<std::string, Accumulator>). At this point I get a compiler errors: /Developer/opt/Boost/1.53.0/include/boost/accumulators/statistics/extended_p_square.hpp: In constructor 'boost::accumulators::impl::extended_p_square_impl<Sample>::extended_p_square_impl(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::count, boost::accumulators::tag::sum, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Sample = double]': /Developer/opt/Boost/1.53.0/include/boost/accumulators/framework/depends_on.hpp:319: instantiated from 'boost::accumulators::detail::accumulator_wrapper<Accumulator, Feature>::accumulator_wrapper(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::count, boost::accumulators::tag::sum, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Accumulator = boost::accumulators::impl::extended_p_square_impl<double>, Feature = boost::accumulators::tag::extended_p_square]' .... I need one accumulator for all the data. I'm using Boost 1.53. How can I create working code? Thanks for help Phil

2 3

Any debugging tips for Boost Interprocess shared memory crashes?
by Warren Postma 14 Jun '13

14 Jun '13

I am a newly humbled mediocre C++ programmer, who is completely unable to figure out why Boost interprocess shared memory classes frequently freeze or crash both at creation and deletion of the manager objects, both with the persistent and the windows-only non persistent versions of the classes. Do you ever debug things and it all just gets worse and worse the longer you try to fix it? http://stackoverflow.com/questions/17100597/does-boostinterprocesswindows-s… Today I am getting crashes in the boost shared memory manager object destructor, or deadlocks in WMI calls. It's in Boost 1.53, on Visual C++ 2008, and involves DLLs. I am unable to reproduce the insanity at a top level EXE demo, and I tried to build a exe-loads DLL1, which loads DLL2, which creates boost objects, which fail when you destroy them, but I am unable to extricate it from my project. So it could be one of the lovely compiler or linker or project settings in my Visual C++ project, something about Multithreaded Debug DLL and MFC and ATL and all the billion varieties of weird RTL and heap bugs that lurk in Visual C++ runtime libraries. I am not blaming boost, but I am at wits end here. I have about 80 hours into debugging this and it's only getting worse the more I look at it. After this I promise to go away, perhaps drink myself silly, and never ever again try to use C++ or boost. Or Windows. Because for all I know this could be a windows SxS issue with Visual Studio 2008 and its lovely assortment of DLLs and runtime SxS insanity. Warren

1 0

boost 1.49.0 on Redhat 5.2 link issues
by Stefan Schwarzer 13 Jun '13

13 Jun '13

Dear everybody, we need to backport boost 1.49.0 to Redhat 5.2. b2 ; b2 install --prefix=/usr/local succeeds and installs libraries and headers in /usr/local as requested (g++ 4.1.2-42, 32 bit PAE kernel). However, we have a problem even linking a mostly trivial example: #include <boost/filesystem.hpp> int main () { copy_file(boost::filesystem::path("atest"), boost::filesystem::path("btest")); } $ g++ testBoost.cpp -lboost_filesystem -lboost_system /tmp/cc10doAS.o: In function `boost::filesystem3::copy_file(boost::filesystem3::path const&, boost::filesystem3::path const&)': testBoost.cpp: (.text._ZN5boost11filesystem39copy_fileERKNS0_4pathES3_[boost::filesystem3::copy_file(boost::filesystem3::path const&, boost::filesystem3::path const&)]+0x24): undefined reference to `boost::filesystem3::detail::copy_file(boost::filesystem3::path const&, boost::filesystem3::path const&, boost::filesystem3::copy_option::enum_type, boost::system::error_code*)' collect2: ld returned 1 exit status The symbol is present in /usr/local/lib/libboost_filesystem and ldconfig does know about its location (see below). Also, trying to link statically or adding -pthread does not change the situation. We are desperate for advice... Roald and Stefan. $ nm -C /usr/local/lib/libboost_filesystem.so | grep 'boost::filesystem3::detail::copy_file' 00010ae0 T boost::filesystem3::detail::copy_file(boost::filesystem3::path const&, boost::filesystem3::path const&, boost::filesystem3::copy_option::enum_type, boost::system::error_code*) $ cat /etc/ld.so.conf include ld.so.conf.d/*.conf /usr/local/lib

2 2

boost::thread::attributes reference overload?
by Anthony Foiani 13 Jun '13

13 Jun '13

Greetings. I have a class that wraps a boost::thread object, and I would like to specify certain thread attributes at construction time. My first attempt looked basically like this: struct my_thread { static boost::thread::attributes getThreadAttr() { boost::thread::attributes attrs; attrs.set_stack_size( 256 * 1024 ); return attrs; } my_thread( Runnable func ) : thread_( getThreadAttr(), func ) {} boost::thread thread_; }; But that fails: g++ -std=c++0x -o thread-attr thread-attr.cpp \ -lboost_thread-mt -lboost_system -pthread ... /usr/include/boost/thread/detail/thread.hpp:191:9: note: \ template argument deduction/substitution failed: thread-attr.cpp:48:42: note: cannot convert ‘my_thread::getThreadAttr()()’ (type \ ‘boost::thread::attributes {aka boost::thread_attributes}’) to type ‘boost::thread::attributes& {aka boost::thread_attributes&}’ Replacing 'getThreadAttr' with a method that returns a non-const reference to internal static variables allows the program to compile and run successfully: static boost::thread::attributes & getThreadAttr() { static boost::thread::attributes attrs; static bool init = false; if ( ! init ) { attrs.set_stack_size( 256 * 1024 ); init = true; } return attrs; } The full program, with Linux compile lines, can be found at the bottom of this message and also at: http://foiani.home.dyndns.org/~tony/boost/thread-attr.cpp I did find a closely-related question on StackOverflow: http://stackoverflow.com/questions/13868619 Where Vicente replied (http://stackoverflow.com/a/13894968/784478) The needed overload template <class F, class Arg, class ...Args> thread(attributes const& attrs, F&& f, Arg&& arg, Args&&... args) is defined only if the compiler supports variadic templates and rvalue references. This could explain your problem. I guess the documentation could be improved to signal this clearly. Please could you create a Trac ticket to follow this issue? However, the compiler I'm using (g++ 4.7.2) has supported both of these features for years. According to this page: http://gcc.gnu.org/projects/cxx0x.html g++ has supported both of these features since 4.3. Josef_K (on freenode IRC #boost channel) was kind enough to try the sample code in their own environment, and they encountered the same errors on both g++ 4.8.1 and clang 3.4. The most likely explanation is that I'm doing something stupid. If anyone has the time to hit me with the clue-by-four, I would appreciate it. There is the possibility that Boost.Thread v4 fixes this (I'm on 1_51_0, which is Boost.Thread v3.0.1). I'd rather not try to transition libraries at this point, but if it has been fixed, confirmation would be welcome. For now, I'll most likely implement the "return reference to internal static" method in my project. It's a bit racy, but since I do all my thread creation through this one routine, I should be able to manage it. Anyway. I'm left feeling that there is a gap somewhere; whether it's in my understanding, in the older version of Boost.Threads, in compiler support / quirks, or elsewhere, I don't know. Regardless, thanks for the excellent library, and happy hacking! Best regards, Anthony Foiani Sample program follows: ======================================================================== // this should work: // g++ -std=c++0x -o thread-attr thread-attr.cpp -lboost_thread-mt -lboost_system -pthread // // this explodes: // g++ -std=c++0x -o thread-attr thread-attr.cpp -DRVALUE_REFERENCE_DOOM -lboost_thread-mt -lboost_system -pthread #include <iostream> #include <boost/function.hpp> #include <boost/thread.hpp> typedef boost::function< void ( void ) > Runnable; struct my_thread { #ifdef RVALUE_REFERENCE_DOOM // this doesn't work. static boost::thread::attributes getThreadAttr() { boost::thread::attributes attrs; attrs.set_stack_size( 256 * 1024 ); return attrs; } #else // this does work, but needs more structure before it can be // considered safe. static boost::thread::attributes & getThreadAttr() { static boost::thread::attributes attrs; static bool init = false; if ( ! init ) { attrs.set_stack_size( 256 * 1024 ); init = true; } return attrs; } #endif my_thread( Runnable func ) : thread_( getThreadAttr(), func ) {} void join() { thread_.join(); } boost::thread thread_; }; void foo() { std::cout << "foo!" << std::endl; } int main( int argc, char * argv [] ) { my_thread t( foo ); t.join(); return 0; }

2 1

Re: [Boost-users] [multi_index] emplace support
by Brian Wood 13 Jun '13

13 Jun '13

> The sad reality is I have very limited time to devote to evolving the > library, so this thing, although in principle simple to implement, has > been procrastinated for years now. Maybe if you sketch the first step that needs to be done here on the list someone will do that and then you can repeat for each step. Whoever would be willing to do this should ask the questions they have here, because there are a number of others on this list who can answer at least some of the questions. A tip to someone willing to do this: Boost Container has emplace support: http://www.boost.org/doc/libs/1_53_0/doc/html/container/move_emplace.html#c… so studying that implementation might be helpful. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net (651) 251-9384

1 0

Output libs to specified folder
by Christopher Pisz 12 Jun '13

12 Jun '13

How can I tell boost to put the libraries in a directory that I specify? If I change stage-dir, it still appends /lib onto it. Is this possible? I want my libraries in C:\trunk\third_party\ Not in C:\trunk\third_party\lib Here is my build script: cd ..\boost SET PATH=$(PATH);..\bjam bjam.exe --stagedir=../../third_party --with-thread toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage bjam.exe --stagedir=../../third_party --with-date_time toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage bjam.exe --stagedir=../../third_party --with-system toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage bjam.exe --stagedir=../../third_party --with-regex toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage bjam.exe --stagedir=../../third_party --with-program_options toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage bjam.exe --stagedir=../../third_party --with-filesystem toolset=msvc-9.0 link=static threading=multi runtime-link=shared variant=debug stage

1 0

[chrono] Initializing system_clock from microseconds
by Kelly, Dan 12 Jun '13

12 Jun '13

I have been having some difficulty initializing a chrono::system_clock::time_point object. Specifically, I am trying to load a time stamp from a .pcap file using libpcap. I have a structure, pcap_pkthdr, which contains two fields: struct timeval { long tv_sec; /* seconds */ long tv_usec; /* and microseconds */ }; struct pcap_pkthdr { struct timeval ts; /* time stamp */ bpf_u_int32 caplen; /* length of portion present */ bpf_u_int32 len; /* length this packet (off wire) */ }; Where tv_sec and tv_usec are seconds and microseconds respectively relative to an epoch of Jan 1, 1970. I can use system_clock::from_time_t() to initialize the time_point to an 64-bit integer seconds (std:time_t). The question is, how do I add the microseconds to this value? My latest attempt is: void my_class::calculate_packet_statistics( const struct pcap_pkthdr *header ) { frame_interval_.intervalTimeStamp_ = system_clock::from_time_t( static_cast<time_t>( header->ts.tv_sec ) ); frame_interval_.intervalTimeStamp_ += microseconds( header->ts.tv_usec ); // This is the problematic line ... } However, this appears to simply add tv_usec to the internal representation of the time_point. The internal representation appears to be in 100ns ticks with an epoch other than Jan 1, 1970. This is on a windows x64 build but the same code will have to work on Linux as well. As a side note, I later do some date calculations using system_clock::to_time_t. I lose my fractional seconds here But since I am only working with dates, this is not a problem. Dan Kelly dan.kelly(a)sig.com ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

2 4

Question about the segfault in path::imbue that is being worked on at the moment
by Lars Hagström 12 Jun '13

12 Jun '13

Hi, I'm being bitten by the bug discussed here http://boost.2283326.n4.nabble.com/filesystem-segfault-in-path-imbue-after-… I'm encountering this when using boost 1.50. I have to support multiple boost versions, so I may bump into this in other versions as well. >From looking at the commit logs of boost svn I see that this is being worked on at the moment. But I would like to know what versions this bug affect, and if there are any ideas for a workaround. To me it looks like it affects most versions of boost filesystem, and I have been unable to come up with a workaround other than removing all use of filesystem in any place that could be called before main() has started. I would really like not having to do that! We use it quite a lot during static initialization... I've tried calling imbue(...) and codecvt() manually before using path, but that doesnt really help. The path_locale is in an anonymous namespace, which stops me from initializing it myself... Any other ideas? Sincerely Lars

1 0

[Interprocess] Interest in a NamedPipe component
by Geoff Shannon 11 Jun '13

11 Jun '13

Hey all, I'm in the early stages of planning an independent study for my CS program and what I'm hoping to do is write a Boost.Interprocess compatible implementation of NamedPipe. However, I don't want what I create to be too closely tied to what I personally want to use. So, if you have any possible interest in utilizing such a feature, please respond and we can chat a bit about what the desirable semantics might be. Specifically I'm interested in comments on what kind of persistence people would lke, and thoughts about whether the stream should be message oriented or not (or optionally so). (see http://www.boost.org/doc/libs/1_53_0/doc/html/interprocess/some_basic_expla… for more info about what I mean by persistence). Right now, my conception of what the key features of a NamedPipe implementation would be is a stream/message oriented communication channel between to unrelated processes. thanks! -- Geoff Nothing is ever easy.

1 0

quantil
by Philipp Kraus 11 Jun '13

11 Jun '13

Hello, I would like to create a box plot and use the static calls of the boost. Median / average etc works well, but I need also the 25% & 75% quantil of my data, I'm using a boost::accumulators::accumulator_set for calculating statistical data. Can I / How can I use this for the quantil calculation or should I do this myself? Thanks Phil

3 9

asio 1.43 ssl client certificate failure
by Stephan Menzel 11 Jun '13

11 Jun '13

Hello all, I am struggling with a bit of an esoteric question and have been debugging for days now. Basically, I am outfitting an existing app with asio based ssl HTTPS. Clients will have to use client authentication. Have my own root CA that signs both client and server certs. Extensive debugging using OpenSSL's s_client and s_server tools shows that the certificate trust chain etc is OK. Server side works fine with browsers, requests client certificate from browsers and only allows access if present. Alas, I can't get the client side to work. in boost 1.43 asio did not yet have any verification callbacks but it does have this: m_ssl_context.set_options( asio::ssl::context::tlsv1_client | asio::ssl::context::default_workarounds ); m_ssl_context.set_verify_mode( asio::ssl::context::verify_peer ); m_ssl_context.load_verify_file( myrootca ); m_ssl_context.use_certificate_file( myclient_cert, asio::ssl::context::pem ); m_ssl_context.use_private_key_file( myclient_key, asio::ssl::context::pem ); When I debug this using openssl s_server I see the connection failing with this message: ... SSL_accept:SSLv3 write certificate request A SSL_accept:SSLv3 flush data read from -0x7ff81be0 [-0x7ff8e2dd] (5 bytes => 5 (0x5)) 0000 - 16 03 01 00 07 ..... read from -0x7ff81be0 [-0x7ff8e2d8] (7 bytes => 7 (0x7)) 0000 - 0b 00 00 03 .... 0007 - <SPACES/NULS> write to -0x7ff81be0 [-0x7ff77a80] (7 bytes => 7 (0x7)) 0000 - 15 03 01 00 02 02 28 ......( SSL3 alert write:fatal:handshake failure SSL_accept:error in SSLv3 read client certificate B 2675716:error:140890C7:SSL routines:SSL3_GET_CLIENT_CERTIFICATE:peer did not return a certificate:s3_srvr.c:3274: ACCEPT A s_client or browser with the exact same keys can connect. Only asio fails and only on the client. Debugging shows that the client won't send the requested SSL certificates to the server. Also, when I register a verification callback in the impl like that: SSL_CTX *ctx = m_ssl_context.impl(); SSL *ssl = m_ssl_socket.impl()->ssl; SSL_CTX_set_client_cert_cb(ctx, &client_certificate_callback); and always return 1 in the callback, it still fails. Unfortunately I cannot upgrade to a post-war boost version and cannot touch OpenSSL either. It is on Windows here and uses OpenSSL 0.9.8i as far as I can see. Am I screwed? Or does anyone have an idea? Much appreciated? Stephan

2 2

[program_options] Can I use shorthand options with more than one char?
by Stefan Köhnen 10 Jun '13

10 Jun '13

Hello, I am currently migrating an old application with some weird command-line arguments. While using Boost program_options, I try to keep some of those arguments from the old version of the application, to assure the compatibility of some user scripts. My problem is that I couldn't find a way to add shorthand options with two or more characters. For example, if I add: ("testOption,to", "This is just a test-option") to the options_description, I only get -t as the shorthand for testOption. Is there some way to use longer shorthand options? Greetings, Stefan Köhnen

1 0

[thread] synchronized_value: value and move semantics
by Vicente J. Botet Escriba 08 Jun '13

08 Jun '13

Hi, boost::synchronized_value (not released yet [1][2][3]) is based on [4]. See below part of this paper adapted to the Boost.Thread interface. Currently boost::synchronized_value is in addition Copyable and Swappable. I was wondering if it is worth adding value and move semantics to synchronized_value. Making it EqualityComparable, LessThanComparable and Movable if the underlying type satisfy these requirements will allow to store them on a Boost.Container/C++11 container. Do you see something completely wrong with this addition? Has some of you had a need for this? Could you share the context? Best, Vicente [1] https://svn.boost.org/svn/boost/trunk/boost/thread/synchronized_value.hpp [2] https://svn.boost.org/svn/boost/trunk/libs/thread/example/synchronized_valu… [3] https://svn.boost.org/svn/boost/trunk/libs/thread/example/synchronized_pers… [4] "Enforcing Correct Mutex Usage with Synchronized Values" by Anthony Williams http://www.drdobbs.com/cpp/enforcing-correct-mutex-usage-with-synch/2252002… ------------- [section The Problem with Mutexes] The key problem with protecting shared data with a mutex is that there is no easy way to associate the mutex with the data. It is thus relatively easy to accidentally write code that fails to lock the right mutex - or even locks the wrong mutex - and the compiler will not help you. std::mutex m1; int value1; std::mutex m2; int value2; int readValue1() { boost::lock_guard<boost::mutex> lk(m1); return value1; } int readValue2() { boost::lock_guard<boost::mutex> lk(m1); // oops: wrong mutex return value2; } Moreover, managing the mutex lock also clutters the source code, making it harder to see what is really going on. The use of synchronized_value solves both these problems - the mutex is intimately tied to the value, so you cannot access it without a lock, and yet access semantics are still straightforward. For simple accesses, synchronized_value behaves like a pointer-to-T; for example: boost::synchronized_value<std::string> value3; std::string readValue3() { return *value3; } void setValue3(std::string const& newVal) { *value3=newVal; } void appendToValue3(std::string const& extra) { value3->append(extra); } Both forms of pointer dereference return a proxy object rather than a real reference, to ensure that the lock on the mutex is held across the assignment or method call, but this is transparent to the user. [endsect] [/The Problem with Mutexes] [section Beyond Simple Accesses] The pointer-like semantics work very well for simple accesses such as assignment and calls to member functions. However, sometimes you need to perform an operation that requires multiple accesses under protection of the same lock, and that's what the synchronize() method provides. By calling synchronize() you obtain an strict_lock_ptr object that holds a lock on the mutex protecting the data, and which can be used to access the protected data. The lock is held until the strict_lock_ptr object is destroyed, so you can safely perform multi-part operations. The strict_lock_ptr object also acts as a pointer-to-T, just like synchronized_value does, but this time the lock is already held. For example, the following function adds a trailing slash to a path held in a synchronized_value. The use of the strict_lock_ptr object ensures that the string hasn't changed in between the query and the update. void addTrailingSlashIfMissing(boost::synchronized_value<std::string> & path) { boost::strict_lock_ptr<std::string> u=path.synchronize(); if(u->empty() || (*u->rbegin()!='/')) { *u+='/'; } } [endsect] [/Beyond Simple Accesses] [section Operations Across Multiple Objects] Though synchronized_value works very well for protecting a single object of type T, nothing that we've seen so far solves the problem of operations that require atomic access to multiple objects unless those objects can be combined within a single structure protected by a single mutex. One way to protect access to two synchronized_value objects is to construct a strict_lock_ptr for each object and use those to access the respective protected values; for instance: synchronized_value<std::queue<MessageType> > q1,q2; void transferMessage() { strict_lock_ptr<std::queue<MessageType> > u1 = q1.synchronize(); strict_lock_ptr<std::queue<MessageType> > u2 = q2.synchronize(); if(!u1->empty()) { u2->push_back(u1->front()); u1->pop_front(); } } This works well in some scenarios, but not all - if the same two objects are updated together in different sections of code then you need to take care to ensure that the strict_lock_ptr objects are constructed in the same sequence in all cases, otherwise you have the potential for deadlock. This is just the same as when acquiring any two mutexes. In order to be able to use the dead-lock free lock algorithms we need to use instead unique_lock_ptr, which is Lockable. synchronized_value<std::queue<MessageType> > q1,q2; void transferMessage() { unique_lock_ptr<std::queue<MessageType> > u1 = q1.unique_synchronize(boost::defer_lock); unique_lock_ptr<std::queue<MessageType> > u2 = q2.unique_synchronize(boost::defer_lock); boost::lock(u1,u2); // dead-lock free algorithm if(!u1->empty()) { u2->push_back(u1->front()); u1->pop_front(); } } [endsect] [/Operations Across Multiple Objects]

2 4

[spirit] Compile error when using qi::locals<>
by Simon 07 Jun '13

07 Jun '13

Hi there, I'm pretty new to spirit and I need a semantic action to construct an object (that's fine) using a vector<double>, the vector is the problem. I'd really appreciate help with this error, or perhaps I'm not using the right technique, in which case, I'd need suggestions on how to proceed. Even if I don't use it anywhere, just adding the following to my grammar base class template parameter and adding the same to the rule declaration I need it for, it gives the monster error below. boost::spirit::qi::locals<std::vector<hs::Language::AX*> > I've also tried to make the vector a pointer, and allocate it on the first semantic action of a sequence. I've searched for an answer but found only one remote reference to boost needing to be recompiled to use c++11 features. So I did, but it didn't change anything (I use boost-1.49.0-r2). Also, I'm not sure if that is right, but my gcc command has this parameter: -std=c++0x I've put the full compile output at this address: http://next.n32.ca/locals.error.txt I will forget it there, so it should still be available in a few weeks/months... ;) And here are a few extracts of just the error lines: /usr/include/boost/spirit/home/qi/nonterminal/grammar.hpp:75:13: error: no matching function for call to 'assertion_failed(mpl_::failed************ (boost::spirit::qi::grammar<Iterator, T1, T2, T3, T4>::grammar(const boost::spirit::qi::rule<Iterator_, T1_, T2_, T3_, T4_>&, const string&) [with Iterator_ = __gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, T1_ = hs::Language::AX*(), T2_ = boost::spirit::unused_type, T3_ = boost::spirit::unused_type, T4_ = boost::spirit::unused_type, Iterator = __gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, T1 = hs::Language::AX*(), T2 = boost::spirit::locals<std::vector<hs::Language::AX*>*>, T3 = boost::spirit::unused_type, T4 = boost::spirit::unused_type, std::string = std::basic_string<char>]::incompatible_start_rule::************)(boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, hs::Language::AX*(), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>))' /usr/include/boost/proto/extends.hpp:537:29: error: use of deleted function 'boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, hs::Language::AX*(), boost::spirit::locals<std::vector<hs::Language::AX*>*>, boost::spirit::unused_type, boost::spirit::unused_type> > >, 0l>::expr()' /usr/include/boost/proto/detail/preprocessed/expr_variadic.hpp:37:12: error: 'boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, hs::Language::AX*(), boost::spirit::locals<std::vector<hs::Language::AX*>*>, boost::spirit::unused_type, boost::spirit::unused_type> > >, 0l>::expr()' is implicitly deleted because the default definition would be ill-formed: /usr/include/boost/proto/detail/preprocessed/expr_variadic.hpp:37:12: error: no matching function for call to 'boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::basic_string<char> >, hs::Language::AX*(), boost::spirit::locals<std::vector<hs::Language::AX*>*>, boost::spirit::unused_type, boost::spirit::unused_type> >::reference()'

3 5

Using boost with 'c' level interfaces ?
by avib369 . 07 Jun '13

07 Jun '13

I can not find any solution where a 'c' api can update/modify a std::vector Passing a std::vector<int>/std::vector<double> to a 'c' or fortran api function, that _reads_, works like a charm. However we are out of luck, if we need the 'c' api, to populate the array. When passing a std::vector will 'kind of' work. But you can never use any of the following // 1/ size() // 2/ empty() // 3/ begin()/ end()/ rbegin()/rend() // 4/ push_back() // 5/ pop_back() You have to separately carry the size of the vector, in order to use it. You then just end up using it like a 'c' array. I thought there may have been way of updating the vectors begin/finish after the api call. But there does not appear to any way to do this. One solution would be to use 'c' array when calling the interface, and then copy to a std::vector. However this would degrade performance, when dealing large data sets. Is there any boost libraries/containers that are applicable or that can handle this issue ? It must have similar properties to a vector, like contiguous memory ? I have included a sample program below, to demonstrate. Before resorting back to 'c' array I was wondering if any one else has come across this problem ? Ta, Avi ============================================================= #include <vector> #include <string> #include <string.h> // memcopy #include <stdlib.h> // malloc #include <iostream> #include <ostream> using namespace std; void c_function_that_reads(int* array, int size_of_array) { for(int i = 0; i < size_of_array; i++) cout << array[i] << ","; cout << "\n"; } void c_function_that_writes(int* array, int size_of_array) { for(int i = 0; i < size_of_array; i++) array[i] = i; } int main(){ { cout << "\ncalling c_function_that_reads\n"; vector<int> dataVec; dataVec.push_back(1); dataVec.push_back(22); c_function_that_reads(&dataVec[0],dataVec.size()); } { cout << "\ncalling c_function_that_writes\n"; int the_size = 10; int* int_array = (int*)malloc(the_size*sizeof(int)); c_function_that_writes(int_array,the_size); // Copy into vector. vector<int> dataVec; dataVec.insert(dataVec.end(), &int_array[0], &int_array[the_size]); for(size_t i = 0; i < dataVec.size(); i++) { cout << dataVec[i] << ","; } cout << "\n"; free(int_array); } { cout << "\ncalling c_function_that_writes\n"; int the_size = 10; vector<int> dataVec; dataVec.reserve(the_size); c_function_that_writes(&dataVec[0],the_size); cout << "dataVec.size() = " << dataVec.size() << ", dataVec.capacity() = " << dataVec.capacity() << " dataVec.empty() = " << dataVec.empty() << "\n"; cout << "for(size_t i = 0; i < dataVec.size(); i++): BROKEN\n"; for(size_t i = 0; i < dataVec.size(); i++) { cout << dataVec[i] << ","; } cout << "\n"; cout << "for(size_t i = 0; i < the_size; i++): WORKS\n"; for(int i = 0; i < the_size; i++) { cout << dataVec[i] << ","; } cout << "\n\n"; cout << "for(vector<int>::iterator i = dataVec.begin(); i != dataVec.end(); i++): BROKEN\n"; for(vector<int>::iterator i = dataVec.begin(); i != dataVec.end(); i++) { cout << (*i) << ","; } cout << "\n"; dataVec.push_back(11); the_size += 1; // dataVec.pop_back(); the_size -= 1; // also broken cout << "for(size_t i = 0; i < dataVec.size(); i++): BROKEN\n"; for(size_t i = 0; i < dataVec.size(); i++) { cout << dataVec[i] << ","; } cout << "\n"; cout << "for(size_t i = 0; i < the_size; i++): BROKEN\n"; for(int i = 0; i < the_size; i++) { cout << dataVec[i] << ","; } cout << "\n\n"; cout << "for(vector<int>::iterator i = dataVec.begin(); i != dataVec.end(); i++): BROKEN\n"; for(vector<int>::iterator i = dataVec.begin(); i != dataVec.end(); i++) { cout << (*i) << ","; } cout << "\n"; // Using std::vector is ok for read only access when calling a c api function // *however* Using a c/fortrans api to *populate* a std::vector leads to issues: // // The following will not work after the api call. // 1/ size() // 2/ empty() // 3/ begin()/ end()/ rbegin()/rend() // 4/ push_back() // 5/ pop_back() // 6/ will ~vector() work since that use begin()/end() ?? // Is it worth using std::vector, since many of invariants are broken ???? // We have to carry the length separately } }

3 2

All talks for Meeting C++ 2013 are online!
by Jens Weller 06 Jun '13

06 Jun '13

1 0

Re: [Boost-users] [1.54.0] Beta 1 Available
by Cromwell Enage 06 Jun '13

06 Jun '13

Hi, all. When calling the merge() member function of a boost::heap::d_ary_heap, is the heap passed in not supposed to be emptied? Here's my test program: ['' #include <boost/heap/d_ary_heap.hpp> #include <boost/heap/binomial_heap.hpp> #include <boost/heap/fibonacci_heap.hpp> #include <boost/heap/pairing_heap.hpp> #include <boost/heap/skew_heap.hpp> #include <boost/test/minimal.hpp> template <typename Heap> void test_heap_merge_memfun() { Heap heap_1, heap_2; heap_1.push(3); heap_1.push(5); heap_1.push(1); heap_2.push(2); heap_2.push(4); heap_2.push(0); heap_1.merge(heap_2); std::cout << " heap_2"; if (!heap_2.empty()) { BOOST_CHECK(4 == heap_2.top()); heap_2.pop(); BOOST_CHECK(2 == heap_2.top()); heap_2.pop(); BOOST_CHECK(0 == heap_2.top()); heap_2.pop(); std::cout << " not"; } std::cout << " emptied." << std::endl; BOOST_CHECK(heap_2.empty()); BOOST_CHECK(5 == heap_1.top()); heap_1.pop(); BOOST_CHECK(4 == heap_1.top()); heap_1.pop(); BOOST_CHECK(3 == heap_1.top()); heap_1.pop(); BOOST_CHECK(2 == heap_1.top()); heap_1.pop(); BOOST_CHECK(1 == heap_1.top()); heap_1.pop(); BOOST_CHECK(0 == heap_1.top()); heap_1.pop(); BOOST_CHECK(heap_1.empty()); } int test_main(int argc, char** argv) { test_heap_merge_memfun< boost::heap::d_ary_heap< int , boost::heap::arity<4> , boost::heap::mutable_<true> > >(); test_heap_merge_memfun<boost::heap::binomial_heap<int> >(); test_heap_merge_memfun<boost::heap::fibonacci_heap<int> >(); test_heap_merge_memfun<boost::heap::pairing_heap<int> >(); test_heap_merge_memfun< boost::heap::skew_heap<int,boost::heap::mutable_<true> > >(); return 0; } ''] When I run this program, I see that all the other heap types empty the heap passed in. I use gcc 4.2.1 with Apple clang version 4.0 on MacOSX 10.8 Cromwell D. Enage

1 0

[Iostreams] Safely returning filtering_istream from function
by Szymon Gatner 06 Jun '13

06 Jun '13

Hi, I would like to return filtering_istream via std::unique_ptr<std::iostream> so that client code can just use iostream interface without knowing what is actual stream type. Inside the factory function filtering_istream is prepared with possible filters attached. Problem is filters are attached by reference. My question is: how to elegantly attach filters to a filtering_istream so that they live as long as filtering_istream itself? How to attach a filter via shared_ptr for example? Regards, Szymon Gatner

2 3

Trouble with posix_time
by Davies, John 06 Jun '13

06 Jun '13

I'm trying to time part of my program and coming up with something I can't explain. I don't expect great accuracy with the sample code here. But I'd like to understand what is happening. static boost::posix_time::ptime MillisecondsFromNow(int milliseconds) { return(boost::posix_time::ptime(boost::posix_time::second_clock::universal_time()) + boost::posix_time::milliseconds(milliseconds)); } Code segment: nanosecond_type const twenty_seconds(20 * 1000000000LL); cpu_timer timer; long count = 0; while(true) { boost::thread::sleep(MillisecondsFromNow(1000)); cpu_times const elapsed_times(timer.elapsed()); nanosecond_type const elapsed(elapsed_times.wall); if (elapsed >= twenty_seconds) { break; } count++; } std::cout << count << '\n'; So I'm running for 20 seconds and delaying each time for a second. So I would expect to get output of 19, maybe 20 or 18. Instead I'm getting around 38-40 I've tried .system and .user and get different values. But never something close to 20. This is on Windows. ___________________________________ John Davies Contractor Home Respiratory Care Philips Home Healthcare Solutions 1740 Golden Mile Highway Monroeville, PA 15146 Email: john.davies(a)philips.com Fax: 724-387-4109 ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

2 1

[DNS] Heads up: svn.boost.org moving to a new server; IP address changing
by Beman Dawes 05 Jun '13

05 Jun '13

At 2:00 pm Eastern US time (i.e 30 minutes from now) we will switch svn.boost.org to a new server with a new IP address. It would be best to hold off on any SVN commits until after the change over, and after your DNS server has the new IP address. If command line "ping svn.boost.org" is going to [129.79.245.252], you are still getting the old IP address. Once svn.boost.org is resolving to [129.79.13.13] it should be OK to resume normal Subversion activity. Thanks, --Beman

1 2

[iostreams] C++ 11 moving semantics
by Ovanes Markarian 05 Jun '13

05 Jun '13

Hello *, I am wondering if latest boost iostreams implementation (1.53) supports C++ 11 moving semantics. I would like to create a tee_device and related stream in a separate function and hide the complexity from the user and just return a stream object which moved out of the function. Any ideas how to do that, without using heap and returning smart pointers? Thanks for your help, Ovanes

1 0

[program_options] Config file and/or response file
by Michael Powell 05 Jun '13

05 Jun '13

Hello, Couple of questions about program options config file (and/or response file). I've got an options set that is starting to get fairly verbose, it's rich, but is also impractical to expect users to type that many options. So I would like to capture some (or all) of those options in one or more different config files, depending on the options that need to be set for a given session. With config files, can the parse_config_file method build a vector of options? For instance if I define "value" as vector<int>, can I specify value=1, value=2, value=3 and expect {1,2,3}? Or does the convention go something like this, value=1 2 3, and so on? Next, how does the parse_config_file method treat boiler plate iterative sections? In other words, if I've got a pattern and would like to capture zero or more of that pattern: [pattern] name=test param=1 expected=2 actual=3 [pattern] name=result param=4 expected=5 actual=6 Those might inform a vector<pattern> type concern downstream of the parser. Possible? Third, in a response file, there is a statement about "limitations", which was left at that. Can we be more specific? What kind of limitations are we talking about? Obvious ones like the delimiters between tokens come to mind, but other than that, that's a nebulous statement at best. Thank you. Regards, Michael Powell

2 1

Nesting bind with shared_ptr<T>::operator* and ref
by Chris Stankevitz 04 Jun '13

04 Jun '13

Hello, Can you please help me uncomment out the last "bind" of the program pasted below? The problem is that it will require some kind of mechanism to dereference the shared_ptr. Thank you, Chris === #include <boost/bind.hpp> #include <boost/function.hpp> #include <boost/make_shared.hpp> #include <boost/shared_ptr.hpp> #include <boost/utility.hpp> using namespace boost; struct C : noncopyable { C() {} void f() {} }; shared_ptr<C> GetC(int) { return make_shared<C>(); } int main() { function<void(C&)> x = bind(&C::f, _1); function<void(shared_ptr<C>)> y = bind(&C::f, _1); // Call x after first computing 42, GetC, and shared_ptr::operator* x(*GetC(42)); // Same as above, but with bind and ref bind(x, ref(*GetC(42)))(); // Similar to above, but delay calling 42, GetC, shared_ptr::operator*, // and ref until later. Also use y (takes a shared_ptr) vs x (that takes // a reference) bind(y, bind(GetC, _1))(42); // Same as above, but use x vs y // todo: add call to operator* // todo: add call to ref // // bind(x, bind(GetC, _1))(42); return 0; }

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[Spirit] Stack overflow, suspect infinite recursion
by Simon 03 Jun '13

03 Jun '13

Hi, I'm writing a math string parser with boost::spirit and I'm stuck on this stack overflow. I've seen this before when I wrote a rule that was misleading. It's the second time I get these and I'm really not sure how I can troubleshoot this kind of problem. Help would be greatly appreciated. I have no issues parsing the forms "A?B" (where A,B are floats and ? is an arithmetic operator +,-,*,/). No issues parsing "(A)" either... At the moment of writing this, I haven't tried but I will be trying to parse simpler forms like "(A)?B" and "A?(B)", "(A?B)", "(A?B)?C" and "A?(B?C)"... I suspect going through them will eventually help me fix the bug with the form below... Below is the final output of my program through valgrind and the rules I have are at the end of my post. I suspect the prob is in the definition for start, operation or operand (an operand may be the result of an operation and an operation is performed on operands). There may be a nasty infinite recursion between operand and operation... The resulting objects are polymorphic and they are correct (as seen when used without spirit). Simon Parsing operations such as ( A?B ) ? ( C?D ) Parsing: (0.1+1.9)+(4.2+6.1) -> (AB=2.000000, CD=10.300000, ABCD=12.300000) ==17013== Stack overflow in thread 1: can't grow stack to 0xb907cfbc ==17013== ==17013== Process terminating with default action of signal 11 (SIGSEGV) ==17013== Access not within mapped region at address 0xB907CFBC ==17013== at 0x13487A: bool boost::spirit::qi::action<boost::spirit::qi::reference<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<char const*, std::string>, std::string ()(), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type> const>, boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::phoenix::composite<boost::phoenix::detail::new_eval<HS::Language::axIdentifier>, boost::fusion::vector<boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > > >::parse<__gnu_cxx::__normal_iterator<char const*, std::string>, boost::spirit::context<boost::fusion::cons<HS::Language::axIdentifier*&, boost::fusion::nil>, boost::fusion::vector0<void> >, boost::spirit::unused_type, boost::spirit::unused_type const>(__gnu_cxx::__normal_iterator<char const*, std::string>&, __gnu_cxx::__normal_iterator<char const*, std::string> const&, boost::spirit::context<boost::fusion::cons<HS::Language::axIdentifier*&, boost::fusion::nil>, boost::fusion::vector0<void> >&, boost::spirit::unused_type const&, boost::spirit::unused_type const&) const (action.hpp:50) ==17013== If you believe this happened as a result of a stack ==17013== overflow in your program's main thread (unlikely but ==17013== possible), you can try to increase the size of the ==17013== main thread stack using the --main-stacksize= flag. ==17013== The main thread stack size used in this run was 96002048. ==17013== Stack overflow in thread 1: can't grow stack to 0xb907cfb8 ==17013== ==17013== Process terminating with default action of signal 11 (SIGSEGV) ==17013== Access not within mapped region at address 0xB907CFB8 ==17013== at 0x48224AC: _vgnU_freeres (vg_preloaded.c:58) ==17013== If you believe this happened as a result of a stack ==17013== overflow in your program's main thread (unlikely but ==17013== possible), you can try to increase the size of the ==17013== main thread stack using the --main-stacksize= flag. ==17013== The main thread stack size used in this run was 96002048. ==17013== ==17013== HEAP SUMMARY: ==17013== in use at exit: 410,754 bytes in 25,628 blocks ==17013== total heap usage: 25,847 allocs, 219 frees, 437,192 bytes allocated ==17013== ==17013== LEAK SUMMARY: ==17013== definitely lost: 409,080 bytes in 25,571 blocks ==17013== indirectly lost: 432 bytes in 27 blocks ==17013== possibly lost: 1,050 bytes in 20 blocks ==17013== still reachable: 192 bytes in 10 blocks ==17013== suppressed: 0 bytes in 0 blocks ==17013== Rerun with --leak-check=full to see details of leaked memory ==17013== ==17013== For counts of detected and suppressed errors, rerun with: -v ==17013== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) Segmentation fault Extract of the grammar: constnum = double_ [_val = new_<axConstant>(_1)]; alpha_numeric = alpha >> +(alnum); ident = alpha_numeric [_val = new_<axIdentifier>(_1)]; operand = ident | constnum | operation; addition = (operand >> lit('+') >> operand) [_val = new_<axAddition>(_1,_2)]; substraction = (operand >> lit('-') >> operand) [_val = new_<axSubstraction>(_1,_2)]; multiplication = (operand >> lit('*') >> operand) [_val = new_<axMultiplication>(_1,_2)]; division = (operand >> lit('/') >> operand) [_val = new_<axDivision>(_1,_2)]; precedence = (lit('(') >> operand >> lit(')')) [_val = new_<axPrecedence>(_1)]; operation = precedence | multiplication | division | addition | substraction; start = operation | operand; } boost::spirit::qi::rule<Iterator, AX*()> start; boost::spirit::qi::rule<Iterator, std::string()> alpha_numeric; boost::spirit::qi::rule<Iterator, axIdentifier*()> ident; boost::spirit::qi::rule<Iterator, axConstant*()> constnum; boost::spirit::qi::rule<Iterator, axOperand*()> operand; boost::spirit::qi::rule<Iterator, axOperation*()> operation; boost::spirit::qi::rule<Iterator, axAddition*()> addition; boost::spirit::qi::rule<Iterator, axSubstraction*()> substraction; boost::spirit::qi::rule<Iterator, axMultiplication*()> multiplication; boost::spirit::qi::rule<Iterator, axDivision*()> division; boost::spirit::qi::rule<Iterator, axPrecedence*()> precedence; };

2 2

Visual Studio Professional 2012
by Scott Alexander 03 Jun '13

03 Jun '13

Hi, Does Boost 1.51 support Visual Studio Professional 2012? I would like to use Boost 1.53 but the latest installer I can find is for 1.51 (from http://www.boostpro.com/download/) Where can I find and installer for the latest version? Thanks, Scott

3 2

Fwd: Compile error using BOOST_FUSION_DONT_USE_PREPROCESSED_FILES
by Fernando Gomes da Silva 03 Jun '13

03 Jun '13

Em quarta-feira, 29 de maio de 2013 17h11min09s UTC-3, Fernando Gomes da Silva escreveu: > > I'm having trouble setting the max template parameters for Boost Fusion > Tuples. > > I've read the source code and found that I can set > BOOST_FUSION_DONT_USE_PREPROCESSED_FILES and set FUSION_MAX_VECTOR_SIZE to > the given number. > > Using MSVC 2012 and using a value of 51, I get the following error: > > \boost_1_53_0\boost\fusion\container\vector\detail\vector_n_chooser.hpp(65): > error C2143: syntax error : missing ';' before '<' > \boost_1_53_0\boost\fusion\container\vector\detail\vector_n_chooser.hpp(66) > : see reference to class template instantiation > 'boost::fusion::detail::vector_n_chooser<T0,T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,T17,T18,T19,T20,T21,T22,T23,T24,T25,T26,T27,T28,T29,T30,T31,T32,T33,T34,T35,T36,T37,T38,T39,T40,T41,T42,T43,T44,T45,T46,T47,T48,T49,T50>' > being compiled > \boost_1_53_0\boost\fusion\container\vector\detail\vector_n_chooser.hpp(65): > error C4430: missing type specifier - int assumed. Note: C++ does not > support default-int > \boost_1_53_0\boost\fusion\container\vector\detail\vector_n_chooser.hpp(65): > error C2238: unexpected token(s) preceding ';' > > Thank you for any inputs! > > Fernando >

1 0

Using boost from XCODE 4.6.1 - what are the proper build settings?
by B Hart 01 Jun '13

01 Jun '13

I downloaded boost 1.53 and extracted to Users/user/Desktop/boost_1_53_0 I built boost as static libraries following instructions at: http://libcinder.org/docs/v0.8.5/_cinder_boost.html I changed XCODE's "Build Settings" "Header Search Paths" to /Users/user/Desktop/boost_1_53_0 as well as the "Library Search Paths" to Users/user/Desktop/boost_1_53_0/stage/lib Then I build and get errors: The first error I'm getting is "has_binary_operator.hpp" Parse issue Expected member name or ';' after declaration specifiers at the line: template < typename Lhs, typename Rhs > struct operator_exists { ... Does anyone have tips for what the build settings should be? The project contains some files that are cocoa/objective C (.m) and others that are C++(.mm) using boost. I'm completely new to trying to use boost under OSX mountain lion and XCODE 4.6.1.

2 1

[mpl] Using max_element inside a fold while constructing a vector
by Brendon Costa 01 Jun '13

01 Jun '13

Hi, I have been using boost.mpl for the first time recently and have solved a number of tasks with boost.mpl now but have a problem with a bit of code I thought should be working. What is wrong with this bit of code using boost.mpl? typedef vector<int_<0>, int_<3>, int_<2> > v1; // I want to use max_element on a vector I am in the process of constructing using a fold typedef typename fold<v1, vector<int_<0> >, push_back<_1, deref<max_element<_1>::type >::type> >::type v2; // This code below compiles and runs fine to illustrate that max_element on a vector works, but is not what I am after. // I thought _1 in the max_element above would be a vector just as v1 below is, but the one below works and the one above does not. // typedef typename fold<v1, vector<int_<0> >, push_back<_1, deref<max_element<v1>::type >::type> >::type v2; I know this code is only going to create v2 like [0, 0, 0, 0] in this case but this is a smaller part of a larger expression that is failing and I cut it down to the minimum to show the problem at hand. In case it is useful I am using gcc 4.5.3 and boost 1.50

2 4

[Thread] Can't compile package_task code with 1.54
by Szymon Gatner 01 Jun '13

01 Jun '13

Hi, I just tried to compile my 1.52- based code with 1.54 beta and run into package_task compilation issue. In 1.52 I was using BOOST_THREAD_VERSION=3 define but with 1.54 I complied with =4. Test program: #define BOOST_THREAD_VERSION 4 #include <boost/thread/future.hpp> #include <boost/function.hpp> struct MyFunc { void operator()()const {} }; int main() { boost::function<void()> f; MyFunc mf; boost::packaged_task<void()> t1(f); // error 1 boost::packaged_task<void()> t2(mf); // error 2 } error 1 being: d:\devel\boost_1_54_0_beta1\boost\thread\future.hpp(2848): error C2664: 'boost::detail::task_object<F,R>::task_object(boost::detail::task_object<F,R> &)' : cannot convert parameter 1 from 'boost::function<Signature>' to 'boost::detail::task_object<F,R> &' and error 2 similarly: d:\devel\boost_1_54_0_beta1\boost\thread\future.hpp(2848): error C2664: 'boost::detail::task_object<F,R>::task_object(boost::detail::task_object<F,R> &)' : cannot convert parameter 1 from 'MyFunc' to 'boost::detail::task_object<F,R> &' (I tried with custom functor because I thought maybe error was related to boost function) Compiling with Visual Studio 2012 Update 3 Regards, Szymon Gatner

2 10

[1.54.0] Beta Release Candidates available
by Marshall Clow 01 Jun '13

01 Jun '13

Release candidate files for 1.54.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: 31266b7dcc6f557ad839e4e87317cd6e *boost_1_54_0_beta1_rc1.tar.gz fbf7be9cbaf9ea6fb21ae73d0c17100d *boost_1_54_0_beta1_rc1.tar.bz2 7de4299ab69c941e83fe3fc46dddc15f *boost_1_54_0_beta1_rc1.zip c73e5118ff585d9f1d68542f96a0758a *boost_1_54_0_beta1_rc1.7z Thanks, --The release managers

4 5

[Xpressive] Nested patterns and sub-matches' semantic values
by Simon 30 May '13

30 May '13

Hi, For one part of a large project, I need to parse math and turn the "mathematical objects" into a C++ abstraction of them. Is it possible that a nested pattern hold semantic values within itself and can be queried for that value somehow? As if a match were a function of its sub-patterns' matches, if that makes sense... Code might speak better than my english: class math_number {...}; class math_addition {...}; class math_arglist {...}; class math_funcdef {...}; sregex integer = (s1= +_d) [ return math_number( as<int>(s1) ) ]; sregex addition = (s1= integer) >> '+' >> (s2= integer) [ return math_addition( as<math_number>(s1), as<math_number>(s2) ) ]; sregex arglist = (s1= identifier) >> *( ',' >> (s2= arglist)) [ std::vector<math_id> ids( as<math_arglist>(s2).begin(), as<math_arglist>(s2).end() ); ids.push_back(as<math_id>(s1)); return ids; ] sregex funcdef = ((s1= identifier) >> '(' >> (s2= arglist) >> ")=" >> (s3= addition)) [ return math_funcdef( as<math_id>(s1), as<math_arglist>(s2), as<math_addition>(s3) ) ]; I just want to avoid the funcdef above to be responsible for the construction of the various math_* objects the funcdef will hold (some of which will be complex to construct). And if I really must store the objects in an external stack, how should the parent-objects find their child-objects? Thanks, Simon

2 2

Confused with BGL-- Six Degrees of Kevin Bacon example
by lizy10b 30 May '13

30 May '13

Hi there, I am new to BGL library. I am walking through the online tutorial and just finished the "10.2. Six Degrees of Kevin Bacon". As it is said at the end of the example: "Note that vertex descriptor objects can not always be used as indices into vectors or arrays such as bacon_number. This is valid with the adjacency_list class with VertexList=vecS, but not with other variations of adjacency_list. A more generic way to index based on vertices is to use the ID property map (vertex_index_t) in coordination with the iterator_property_map.". So I turn to have a look at the iterator_property_map page and its sample. First, this sample uses VertexList=vecS too. Second, I know this sample is using iterator_property_map to build a property map, but I think the property is still indexed by the edge descriptor objects. So what is the difference? Thanks. Zhiyu LI 2013-05-29 lizy10b

2 5

[program options] parsing std::string
by Michael Powell 30 May '13

30 May '13

Hello, I want to parse std::string, perhaps into a vector<string>, but I do not want the command line argument to be positional in nature (i.e. like the examples demonstrate), because there may be a handful of parameters I need to capture into string or vector<string>. I've been able to parse integral types like int, even vector<int>, but haven't had much success with string. Possible or is this a program options "feature" and/or bug? Regards, Michael Powell

2 1

Does the Proactor of boost uses edge-triggered epoll on linux?
by Journeyer J. Joh 30 May '13

30 May '13

Hello list, I have some questions about boost's async IO implementation for linux. 1. Does it use edge-triggered epoll to implement the Proactor (in terms of Reactor)? http://www.boost.org/doc/libs/1_53_0/doc/html/boost_asio/overview/core/asyn… The guide above says that boost's Proactor is implemented in terms of Reactor when it comes to Linux. If it is based on Reactor, I guess it should be level-triggered epoll. 2. Am I right? Then my question is 3. Does boost use edge-triggered epoll in any kind of async IO on linux? 4. Isn't edge-triggered epoll a good method to implement async IO on linux? Thank you very much. Sincerely Journeyer ---------------------------------------- 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 ----------------------------------------

3 5

Install Boost.Build: gcc command not found (Windows)
by Tom C 29 May '13

29 May '13

I'm trying to build boost from sources following this guide: "http://www.boost.org/doc/libs/1_53_0/more/getting_started/windows.html#or-b…" I got the following outputs: here is bootstrap.log: here is my C:[...]\boost_1_53_0\tools\build\v2\user-config.jam: here is my PATH: It seems like the user-config.jam is not read by the bootstrap command. -- View this message in context: http://boost.2283326.n4.nabble.com/Install-Boost-Build-gcc-command-not-foun… Sent from the Boost - Users mailing list archive at Nabble.com.

3 2

Re: How to Boost static lib build under Mountain Lion and XCODE 4.6
by B Hart 27 May '13

27 May '13

Hi, I'm trying to install and use Boost 1_53_0 on MAC OS X Mountain Lion and use it with the latest XCODE 4.6.x. I want to port a small MS VS MFC C++ app. I developed on Windows to MAC. Specifically I need to install and build boost as static libraries. I'm completely new to programming on the MAC side of things. I understand that XCODE now uses LLVM Clang, with libc++ and not GCC. I've used GCC on Linux. I started following the instructions at: http://www.boost.org/doc/libs/1_53_0/more/getting_started/unix-variants.html but quickly ran into trouble. Does anyone have detailed instructions for how to install and compile boost statically under Mountain Lion and XCode 4.6? Below is the terminal input and output showing how far I got. Thanks. Terminal IO: ./bootstrap.sh --with-bjam=BJAM --with-toolset=TOOLSET users-Mac-mini:boost_1_53_0 user$ ./bootstrap --with-bjam=BJAM --with-toolset=TOOLSET -bash: ./bootstrap: No such file or directory users-Mac-mini:boost_1_53_0 user$ ./bootstrap.sh --with-bjam=BJAM --with-toolset=TOOLSET -n Detecting Python version... 2.7 -n Detecting Python root... /System/Library/Frameworks/Python.framework/Versions/2.7 -n Unicode/ICU support for Boost.Regex?... not found. Generating Boost.Build configuration in project-config.jam... 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://www.boost.org/more/getting_started/unix-variants.html - Boost.Build documentation: http://www.boost.org/boost-build2/doc/html/index.html users-Mac-mini:boost_1_53_0 user$ ./b2 link=static threading=multi toolset=darwin cxxflags="-arch i386 -arch x86_64" macosx-version=10.6 stage -bash: ./b2: No such file or directory

2 3

Using boost.Test check_is_small for my own
by Olaf Peter 26 May '13

26 May '13

Hello, I try to use parts of boost.test lib not for unit testing self but inside an algorithm. Anyway, at the end of header http://www.boost.org/doc/libs/1_53_0/boost/test/floating_point_comparison.h… this is written inside anonymous namespace it works obviously, but not at me. What happened here and how to fix it? Did I not read the header carefully? Thanks, Olaf ---8<---- #include <boost/test/floating_point_comparison.hpp> namespace tools { using boost::test_tools::check_is_small_t; check_is_small_t const& check_is_small = unit_test::ut_detail::static_constant<check_is_small_t>::value; } int main() { bool ok = tools::check_is_small(900, 0.1); } --->8---- test.cpp:5:30: error: 'boost::test_tools::check_is_small_t' has not been declared test.cpp:7:5: error: 'check_is_small_t' does not name a type test.cpp: In function 'int main()': test.cpp:12:15: error: 'check_is_small' is not a member of 'tools'

2 1

variant visitor using SFINAE problem
by Olaf Peter 26 May '13

26 May '13

Hi, attached my code to show my problem. It seems to work (partially) so far, but not the vector<int> where I get a compile error. This is my first try with SFINAE in that way. Are the conditions correct and robust enough? How to compile it? Did I forgot one use case? Using this small helper would simplify some post processing. Thanks, Olaf

2 4

[thread] "almost works" clarification
by Michael Powell 26 May '13

26 May '13

Hello, Okay, so without starting a flame war, because that is not my intention... Also bear in mind, I am coming from an informed C# .NET frame of mind having worked with .NET threading, synchronization, events, and so forth. I ran across this article, which although a bit dated, is a pretty good sketch of what I would consider a fairly robust thread runner abstraction, which if you read past the frustration, makes good sense, at least in my opinion: http://peter.bourgon.org/blog/2008/12/12/boost-thread-kindof-sucks.html. Nothing against the author, I might turn that around and couch it instead: boost-thread-almost-works: in the sense that, while there are indeed a rich set of primitives provided to hide the details of pthread, Win32 threading, or what have you, it stops just short of providing that abstraction layer for what Peter and I (probably just he and I) consider a robust runner, monitor, and worker. The ingredients are there, though, and with a little bit of persuading, can compose a fairly robust little set of threaded runners. Okay, with that said, am I correct in understanding, the combination of condition and mutex facilitates the analog to C# .NET AutoResetEvent or ManualResetEvent (loosely, ResetEvent) type thing? In other words, thread keeps-on-a-runnin' until condition is notified, at which point thread loop(s) know to stop working when they check in with their conditioned mutex? In other words, mechanically speaking, a worker-bee that starts obtains a lock on the mutex. While the worker is running, on-lookers may poll the monitor for thread completion (which times out as long as the worker-bee is running and has a scoped lock), or otherwise signal the thread to complete through the notify mechanism (which tells the worker-bee to return, which clears the lock). The worker-bee runs until it is completed or its conditioned mutex has been notified (whichever comes first). In another rendition, I was actually using the thread-interruption mechanism, which I may still do, is another way of signaling a thread that it should stop what it's doing. However, seems a bit less graceful than routing requests through a formalized abstraction layer I think, except through creative use of interrupt disabled (which I was also using), but is something else to consider. Anywho, food for thought. Comments, critiques welcome. Thank you... Regards, Michael Powell

4 5

[ublas] Linkage problems in assignment.hpp
by Jérémy Coulon 25 May '13

25 May '13

Hello, Is there any chance for the following bug to be fixed in 1.54 ? https://svn.boost.org/trac/boost/ticket/6010 Thanks. Jérémy

1 0

boost 1.53 parallel graph samples build or test failure on windows
by lizy10b 25 May '13

25 May '13

Hi there, I am a windows user and facing the similar problem as decribled in an archived thread posted by Jeremiah Willcock in 2010, but with no practical solutions: "Result statuses for run failures of MPI tests" http://boost.2283326.n4.nabble.com/Result-statuses-for-run-failures-of-MPI-… My environment: Boost 1.53, Win7 x64, mpich2-1.3.2p1-win-ia32, Python 2.66 x86, VS2010 SP1 The content of the user-cofig.jam file used to compile boost is: using python : 2.6 : C:\\Python266 ; using mpi : : <find-static-library>mpi <library-path>"D:\\Program Files (x86)\\MPICH2\\lib" <include>"D:\\Program Files (x86)\\MPICH2\\include" : "\"D:\\Program Files (x86)\\MPICH2\\bin\\mpiexec\"" ; and the bjam command is: bjam --prefix=E:\boost_1_53_0\debug32 stage toolset=msvc-10.0 variant=debug link=static address-model=32 threading=multi I did not use the bjam self-test to test all the parallel graph samples, but only picked some samples and build them in VS2010 and try to run. The dependencies linked in VS2010 when build these samples are: mpi.lib libboost_graph-vc100-mt-gd-1_53.lib libboost_graph_parallel-vc100-mt-gd-1_53.lib libboost_mpi-vc100-mt-gd-1_53.lib libboost_mpi_python-vc100-mt-gd-1_53.lib mpi-vc100-mt-gd-1_53.lib Testing results: No. Sample Name Build 1 proc test 2 proc test -------------------------------------------------------------------- 1 adjlist_redist_test.cpp Passed No Error No Error ----------------------------------------------------------------------- 2 adjlist_build_test.cpp Passed Error Error Error Message: Building graph with add_edge from everywhere...application called MPI_Abort(MPI_COMM_WORLD, -1) - process 0 application called MPI_Abort(MPI_COMM_WORLD, -1) - process 1 job aborted: rank: node: exit code[: error message] 0: lee-win7-x64: -1: process 0 exited without calling finalize 1: lee-win7-x64: -1: process 1 exited without calling finalize ----------------------------------------------------------------------------- 3 breadth_first_search.cpp Error -- -- Error Message: error LNK2019: unresolved external symbol "void __cdecl boost::detail::bfs_helper<class boost::adjacency_list<struct boost::vecS... ------------------------------------------------------------------------------ 4 dijkstra_shortest_paths.cpp Passed No Error No Error ------------------------------------------------------------------------------- 5 distributed_csr_test.cpp 18 Errors -- -- Error Messags (3 of 18): Error 5 error C2039: 'key_type' : is not a member of 'boost::property_traits<PA>' e:\boost\boost_1_53_0\debug32\include\boost-1_53\boost\graph\distributed\compressed_sparse_row_graph.hpp 1904 1 boost_test_1 Error 6 error C2146: syntax error : missing ';' before identifier 'local_key_type' e:\boost\boost_1_53_0\debug32\include\boost-1_53\boost\graph\distributed\compressed_sparse_row_graph.hpp 1904 1 boost_test_1 Error 12 error C2602: 'boost::property_map<Graph,Property,Enable>::value_type' is not a member of a base class of 'boost::property_map<Graph,Property,Enable>' e:\boost\boost_1_53_0\debug32\include\boost-1_53\boost\graph\distributed\compressed_sparse_row_graph.hpp 1906 1 boost_test_1 ----------------------------------------------------------------------------------------- So where is the problem? Any help is appreciated. Thanks Zhiyu Li Student China 2013-05-25 lizy10b

1 0

[Test] How to span tests into multiply files
by Daniele Barzotti 24 May '13

24 May '13

Hi, I want to divide my test suites into multiply files. I follow this example: http://stackoverflow.com/questions/2906095/boost-test-looking-for-a-working… testmain.cpp ----------------- #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE Main #include <boost/test/unit_test.hpp> testConfigClass.cpp ----------------- BOOST_AUTO_TEST_SUITE(ConfigClass_TestSuite) BOOST_AUTO_TEST_CASE(testConfigClass) { ... } BOOST_AUTO_TEST_SUITE_END() testDispatcherClass.cpp ----------------- BOOST_AUTO_TEST_SUITE(DispatcherClass_TestSuite) BOOST_AUTO_TEST_CASE(testDispatcherClass) { ... } BOOST_AUTO_TEST_SUITE_END() Maybe in the testConfigClass I have some problems, which I cannot figure out. When the test ends, the program terminate with: Exception first-chance a 0x7569c41f in TestSuite.exe: Exception of Microsoft C++: boost::execution_exception into memory position 0x0034dda4.. In this scenario, where can I found the 'main' to debug deeply? BR, Daniele.

2 1

[thread] SEVERE bug on packaged_task constructor in C++11 mode.
by Vicente J. Botet Escriba 23 May '13

23 May '13

Hi, There is a severe bug in packaged_task constructor when compiling in C++11 mode and giving a copyable functor as parameter, as reported in https://svn.boost.org/trac/boost/ticket/8596. I believe that this is not a regression, this have never worked. Until I find a fix, the packaged_task could be used only with free functions and with movable functors when compiling in C++11 mode. Fortunately there is no regression on C++98 compilers (at least not identified yet). Sorry for the disagreement, Vicente

2 1

[SmartPtr] shared_ptr as a default value in function template
by Igor R 23 May '13

23 May '13

Hello, In the wake of one of recent SO posts... The following doesn't compile in MSVC10 (Boost 1.53): #include <boost/shared_ptr.hpp> #include <boost/make_shared.hpp> template<class T> void f(T item, boost::shared_ptr<int> name = boost::make_shared<int>()) { } int main() { f(0); } Is it a bug in make_shared or the above violates some Standard paragraph? Thanks.

3 4

Is boost::this_thread::sleep_for interruption point?
by Serg Gulko 23 May '13

23 May '13

Hello! According to documentation(v 1.50.0) call boost::this_thread::sleep_for can be interrupted. For some reason this functionality not works for me. Here is code sample: //Simple thread function void Test::worker(int delay) { try { boost::this_thread::sleep_for(boost::chrono::milliseconds(delay)); cout << "Doing some work" << endl; } catch (boost::thread_interrupted const& e) { cout << "INTERRUPTED" << endl; } } //Far in the code boost::thread workerThread(boost::bind(&Test::worker, this, 1200)); boost::this_thread::sleep(boost::posix_time::milliseconds(30)); workerThread.interrupt(); boost::this_thread::sleep(boost::posix_time::milliseconds(1500)); I always getting 'Doing some work'... -- View this message in context: http://boost.2283326.n4.nabble.com/Is-boost-this-thread-sleep-for-interrupt… Sent from the Boost - Users mailing list archive at Nabble.com.

3 3

[msm] Manually setting next state
by samriti katoch 22 May '13

22 May '13

Thanks for the reply Christophe. I had considered this alternative, but adding a transition in every state to the initial state, when Error -> Ok defeats the purpose of having an orthogonal region, which I added to basically reduce transitions on an Error. -Samriti

1 0

Compile errors including boost/regex.hpp
by Jordan H. 22 May '13

22 May '13

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 When I try to compile a file that includes <boost/regex.hpp> I get the following error: # /home/me/Projects/myproject> make # /usr/bin/make all-am # make[1]: Entering directory `/home/me/Projects/myproject' # compiling main.cpp (g++) # In file included from /usr/local/include/boost/regex/regex_traits.hpp:27:0, # from /usr/local/include/boost/regex/v4/regex.hpp:39, # from /usr/local/include/boost/regex.hpp:31, # [ ... more traceback ... ] # # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: macro "test" passed 2 arguments, but # takes just 1 # In file included from /usr/local/include/boost/regex/v4/regex.hpp:79:0, # from /usr/local/include/boost/regex.hpp:31, # [ ... more traceback ... ] # # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: macro "test" passed 2 arguments, but # takes just 1 # In file included from /usr/local/include/boost/regex/regex_traits.hpp:27:0, # from /usr/local/include/boost/regex/v4/regex.hpp:39, # from /usr/local/include/boost/regex.hpp:31, # [ ... more traceback ... ] # # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: template declaration of ‘char (& # boost::re_detail::test)[2]’ # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: expected unqualified-id before ‘...’ # token # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: expected ‘)’ before ‘...’ token # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: expected ‘)’ before ‘...’ token # /usr/local/include/boost/regex/v4/regex_traits.hpp:87:1: error: expected unqualified-id before ‘(’ # token # In file included from /usr/local/include/boost/regex/v4/regex.hpp:79:0, # from /usr/local/include/boost/regex.hpp:31, # [ ... more traceback ... ] # # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: template declaration of ‘char (& # boost::re_detail::test)[2]’ # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: expected unqualified-id before ‘...’ # token # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: expected ‘)’ before ‘...’ token # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: expected ‘)’ before ‘...’ token # /usr/local/include/boost/regex/v4/regex_format.hpp:849:1: error: expected unqualified-id before ‘(’ # token # make[1]: *** [myproject-main.o] Error 1 # make[1]: Leaving directory `/home/me/Projects/myproject' # make: *** [all] Error 2 # *** Failure: Exit code 2 *** This is how I'm compiling: # g++ -DHAVE_CONFIG_H -I. `mysql_config --include` `mysql_config --cflags` -std=c++0x -g -O2 -MT # myproject-main.o -MD -MP -MF .deps/myproject-main.Tpo -c -o myproject-main.o `test -f 'src/main.cpp' # || echo './'`src/main.cpp Basically, the compile errors trace back to when I include boost/regex.hpp: | #include <boost/regex.hpp> Any ideas why this occurs? Maybe it's because I'm not including -lbooost_regex as a compile option? I specified it as my "myproject_LDADD" macro in Makefile.am so I assume g++ knows when to use it. Thanks. Sorry for the lengthy email. -----BEGIN PGP SIGNATURE----- iQEcBAEBCgAGBQJRnN/nAAoJEOT99oqiSuRNim0H/1U+xgx+TCwOtDiGfC5FH6yR 1HwZYwTb0F/7CwldOBsPoDMfjSJmptH4a4s84PR0xDHFrhvgDkjDvzYkoWPLR7gf eSAMHzQG3kvJawvHiJNSu/eTZivVfkCE14+zoE+cVriCJicJUJg1g8hp5Cydk6D3 OM9WtOY/GCVHD8lK84UX5HMqnjeX4nPLEA7nJGd1u2+5PkHxpQMF2RO+EWnlNm0e eTUdZBlGLc/RGHMgl2uF1q3b+qCRrC/Wwn/4OtkDUn0Y3V879LbkYej06oB94zWD 9kKHAnTFOisQJDUmkHr9BiEGgJ9UNO2JCVkHlzrjVgfwKe1r6FIaZmTGNpIme0c= =Av+g -----END PGP SIGNATURE-----

3 6

[msm] Manually setting next state
by samriti katoch 22 May '13

22 May '13

Hi, Is there a way to manually set the next state for the state machine. I have an orthogonal region defined for handling errors, where Error is an interruptible state. ---------- ------------- | | ----------->| Error | | Ok | | | ---------- ------------- This is similar to the example here : http://svn.boost.org/svn/boost/trunk/libs/msm/doc/HTML/examples/Orthogonal-… Once the state machine recovers from the error, I would like to start from the initial state again in the main orthogonal region. Is there a way to do this ? Thanks! Samriti

2 1

[atomic] When to load/store
by Michael Powell 22 May '13

22 May '13

Hello, I have some thread synchronization to do, probably will end up using some sort of internally synchronized cancelation or other state to message between parent and child thread. If the state uses boost::atomic<bool> _canceled, for instance, how do I go about setting/getting the value? I am assuming that we do something like this: //To get the value. return _canceled.load(boost::memory_order::memory_order_acq_rel); //To set the value. _canceled.store(canceled, boost::memory_order::memory_order_acq_rel); Using acquire/release to get in, do what we need with the value, and get out, type thing. Also bearing in mind this is targeting ARM architecture (ARM5 I think). Also, how complex a value can be protected? Are we talking primitive types only? Basic data types like bool, int, float, that sort of thing? Thank you... Regards, Michael Powell

2 1

[Atomic] / PPC / error: impossible constraint in 'asm'
by nicolas.danet＠free.fr 22 May '13

22 May '13

Hello, I get the error below compiling with (Xcode 2.5 / OS X 10.4.11) only for PPC arch. boost_1_53_0/boost/atomic/detail/gcc-ppc.hpp:1204: error: impossible constraint in 'asm' The related code is: static boost::atomic<long> messageCount_(0); number_ = messageCount_.fetch_add(1, boost::memory_order_relaxed); Is this a known bug ? Is there any way to fix it ? Thanks.

1 0

[accumulator] with complex domain model
by Michael Powell 21 May '13

21 May '13

Hello, We've got a complex domain model which must be accumulated and eventually averaged together. I am already overloading the operators for that model. We could roll our own with just the operators we'll need to accommodate, like +, +=, /, etc, but would like to take a gander at Boost.Accumulator first. Would be much better, obviously, rather than having to reinvent the wheel. How doable would it be to accumulate an arbitrarily complex domain model. That's assuming that it is sensible to add, average, and so on, the model, which it is. Regards, Michael Powell

2 2

endless loop and/or crash in boost::interprocess
by Charanga 21 May '13

21 May '13

How do I debug a potential endless loop and heap corruption issue involving boost::interprocess "new managed_shared_memory" freezing forever or crashing? I posted this on stackoverflow but I am hopeful that a real expert in Boost::Interprocess may have seen this freeze-up and crash before. Outside the debugger it manifests as a freeze-up, inside the debugger it manifests as a series of exceptions inside an endless try-catch-ignore loop which is coded into the boost implementation code. http://stackoverflow.com/questions/16651878/how-do-i-debug-a-potential-endl… Warren

2 1

[SmartPtr] enable_shared_from_raw / weak_from_raw remains not associated
by Slava 20 May '13

20 May '13

I'm converting existing code with parent-child object tree to boost shared_ptr/weak_ptr with parents having [now shared] ownership over the children and children having weak reference to the parent. In the existing code a parent usually becomes the children as constructor parameters, and thus I have to extract the weak_ptr to "this" in constructor, which does not work with current boost::enable_shared_from_this implementation. So I am looking to enable_shared_from_raw alternative, which is promising, but unfortunately does not quite work for my case. Here is a small example demonstrating the issue: test.cpp: #include <boost/smart_ptr/enable_shared_from_raw.hpp> #include <iostream> struct Parent; struct Child { Child() { std::cout << "Construct Child" << std::endl; } ~Child() { std::cout << "Destruct Child" << std::endl; } boost::weak_ptr<Parent> parent; }; struct Parent : public boost::enable_shared_from_raw { Parent(boost::shared_ptr<Child> _child) { std::cout << "Construct Parent" << std::endl; this->child = _child; this->child->parent = boost::weak_from_raw(this); } ~Parent() { std::cout << "Destruct Parent" << std::endl; } boost::shared_ptr<Child> child; }; int main() { boost::shared_ptr<Child> child(new Child()); boost::shared_ptr<Parent> parent(new Parent(child)); std::cout << "child->parent is " << (child->parent.lock() ? "not null" : "null") << std::endl; parent.reset(); std::cout << "child must be alone" << std::endl; std::cout << "child->parent is " << (child->parent.lock() ? "not null" : "null") << std::endl; return 0; } `g++ -g -O0 test.cpp && valgrind a.out` produces: ==8467== Memcheck, a memory error detector ==8467== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al. ==8467== Using Valgrind-3.8.1 and LibVEX; rerun with -h for copyright info ==8467== Command: a.out ==8467== Construct Child Construct Parent child->parent is null Destruct Parent child must be alone child->parent is null Destruct Child ==8467== ==8467== HEAP SUMMARY: ==8467== in use at exit: 0 bytes in 0 blocks ==8467== total heap usage: 4 allocs, 4 frees, 112 bytes allocated ==8467== ==8467== All heap blocks were freed -- no leaks are possible ==8467== ==8467== For counts of detected and suppressed errors, rerun with: -v ==8467== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2) The problem is that the weak_ptr to parent in child does not get associated properly, when shared_ptr to parent is finally complete. Do I expect too much from enable_shared_from_raw or did I hit some bug in the implementation? I'm using boost 1.53.0-2 on Archlinux. -- Slava

2 3

[boost][thread] Future's scheduler
by Klaim - Joël Lamotte 20 May '13

20 May '13

I'm using boost.thread V4 in my projects because I would like to use futures. I understand that boost 1.53 implementation of future.then() is incomplete but I think it's ok for my current use. However I think there might be something missing. I'm in a case where the user of my library provide his own task scheduler (or executor) which means that when I have functions that return futures, they will use that scheduler. I would like to limit the boilerplate necessary for the user to schedule tasks properly when one task is finished, so I assume the user will use then() with just lambdas or function pointers. The documentation of then() says: - When the scheduler or launch policy is not provided the continuation inherits the parent's launch policy or scheduler. Which is perfect to me as I just have to associate the first future with the scheduler, the user that will use .then() will not have to specify which scheduler to use. My problem is that I can't find how to associate a scheduler to a future (without using .then()). There is apparently no way to do this in boost::future or boost::promise interfaces. Am I missing something? I see that I could use a dummy initial future just to build another future with .then() which would associate the second future with the scheduler, but this is clearly just ductapping. Joel Lamotte

1 1

64 bit or 32 bit?
by Scott Alexander 20 May '13

20 May '13

Hi, I have a Windows 8 64 bit OS and would like to use Visual Studio Express 2012 for Windows 8. Should I install a 64 bit or 32 bit version of Boost? Thanks, Scott

4 4

[asio] schedule work on all threads of a single io_service::run() pool?
by Anthony Foiani 18 May '13

18 May '13

Greetings -- Is there a way to ask the io_service to distribute a particular handler to every thread that is running the service? My use case is per-thread watchdogs, and I need the worker threads to ping the watchdog on some regular interval (e.g., every 5 seconds). I didn't see anything like this in the docs, and I didn't see anything that looked promising when I looked through the source. (I'll freely admit that the ASIO source is beyond my ability to comprehend it without much more study, however.) I can approximate it by having my worker threads do something like this (pseudocode): while ( true ) { boost::system::error_code ec; io_service::poll_one( ec ); if ( ec == stopped ) break; watchdog::ping(); sleep( 500ms ); // trying to balance lag and wakeups } But that has the obvious problems of lag and more wakeups than I really need. To make this hack work, I think I need some calls that probably don't exist; instead of that "sleep" call, I would like to be able to do something like a timed wait on a condition variable: io_service::all_threads_cond.timed_wait( 5s ); That way, I would only wake up every 5 seconds (to feed the watchdog), unless the io_service sent a "notify_one" to the condition variable and this thread happened to be picked. Extra pings aren't much of an issue, but it would be nice to minimize them. Anyway. I'll continue digging, but if anyone has suggestions, I'd love to hear them. Thanks in advance! Best regards, Anthony Foiani

2 5

[smart_ptr] Migrating from boost::shared_ptr<> to std::shared_ptr<>
by Szymon Gatner 18 May '13

18 May '13

Hi, with recently acquired (semi) C++11 compiler (YEY!) I started to think which of BOOST functionality could be replaced by standard counterparts. First obvious candidates are smart pointers. Thing is, there is lots of functions that take boost::shared_ptr<> as arguments (or return them) and it is just not easy to do do. My questions: - does it even make sense to switch to std::shared_ptr<> (should new functions use std instead of boost) - is there a way to easily convert one to another - what are (if any) differences between std and boost versions Regards, Szymon Gatner

2 1

(no subject)
by Yeni Lora 18 May '13

18 May '13

Hi I have a problem with my code I using mpi. The error is with mca_btl_tcp_frag_recv, and I don´t know what mean... The error complete [../../../../../../ompi/mca/btl/tcp/btl_tcp_frag.c:216:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv: readv failed: Connection timed out (110) and [btl_tcp_frag.c:216:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv: readv failed: Connection reset by peer (104) I need some help...

4 3

[lockfree] overwriting push?
by Rich E 18 May '13

18 May '13

I'm using boost::lockfree::spsc_queue in an audio graph to allow audio input samples written from one thread to be read from another. This currently looks like: #include <boost/lockfree/spsc_queue.hpp> class RingBuffer { public: RingBuffer() : mLockFreeQueue( 0 ) {} RingBuffer( size_t size ) : mLockFreeQueue( size + 1 ), mSize( size ) {} ~RingBuffer() {} //! pushes to buffer, overwriting oldest samples void write( const float *samples, size_t count ) { if( count > mSize ) { count = mSize; } size_t numPushed = mLockFreeQueue.push( samples, count ); if( count > numPushed ) { size_t numLeft = count - numPushed; // ???: is there a more efficient way to overwrite? float old; for( int i = 0; i < numLeft; i++ ) { mLockFreeQueue.pop( old ); } numPushed = mLockFreeQueue.push( &samples[numPushed], numLeft ); assert( numPushed == numLeft ); } } size_t read( float *samples, size_t count ) { if( count > mSize ) { count = mSize; } return mLockFreeQueue.pop( samples, count ); } private: boost::lockfree::spsc_queue<float> mLockFreeQueue; size_t mSize; }; If there is not enough space in the write call, I sequentially pop off elements until there is enough. Is there a better way to do this? It seems like there should be a mechanism for just moving the read head forward (atomically) without reading anything, but then I am not sure I completely understand the implications of that on the lockfree model. I'm also not 100% sure this is adhering to the lockfree model, so please inform me if/how it isn't if you know. Thank you for your time, Rich

2 2

[BGL] assert( source(* (out_edges(v, undigraph).first), undigraph) == v )
by Andreas Fabri 17 May '13

17 May '13

Hello, When I have an undirected graph, for edge_descriptor source and target still are defined. That is stated here: http://www.boost.org/doc/libs/1_53_0/libs/graph/doc/graph_concepts.html My question. Is edge_descriptor ed = * out_edges(v,undigraph).first; Is there a requirement for graph implementations that source(ed,g) == v ? best regards, andreas -- Andreas Fabri, PhD Chief Officer, GeometryFactory Editor, The CGAL Project phone: +33.492.954.912 skype: andreas.fabri

2 1

which library to use:cleaning up singletons
by Littlefield, Tyler 17 May '13

17 May '13

hello all: I have a fairly large code base that has a lot of modules and systems. The problem is that I have a main "engine" object that holds pointers to a lot of created modules and components. I'm trying to find a more dynamic way to do this, and I thought boost might be able to help. As a result, I have a couple of questions. First, I do a lot of manual adding of features. For example, when I add a new command I have to add a engine->commands.AddCommand(new CMDFoo()); in an initialization method. Does boost provide some sort of mechenism for dynamically handling this? I also plan on splitting up the main "engine" object and setting up the external modules as singletons. They act alone, but again I'd like to dynamically initialize these. Is there a way on entry to dynamically call specific singleton initialization methods, then at exit call their release methods? I'd like to be able to set some sort of trait on these objects at compile-time that the runtime can use, or somehow generate the calls at compile-time. Thanks in advance for any info, -- Take care, Ty http://tds-solutions.net He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave. Sent from my Toaster (tm).

1 0