December 2008 - Boost-users - lists.preview.boost.org

[multiindex] custom key extractor problem
by Stephan Menzel 04 Dec '08

04 Dec '08

Hi everyone, I could need a little advice using boost multiindex as follows: I have a Host class and I want to store HostPtrs in a multiindex container to a) have a member ip() as a key to unique hosts and b) be able to access random hosts via operator[]. The problem as I understand is the shared_ptr. Please consider this: class Host { public: Host(const boost::asio::ip::address &ip) : m_ip(ip) {}; const boost::asio::ip::address &ip(void) const throw () { return m_ip; }; private: Host(void) {}; boost::asio::ip::address m_ip; }; typedef boost::shared_ptr<Host> HostPtr; struct lthost { bool operator()(const HostPtr &h1, const HostPtr &h2) const { return (h1->ip() < h2->ip()); } }; struct giveip { // this is supposedly my key extractor typedef boost::asio::ip::address result_type; const result_type &operator()(const HostPtr &p) const { return p->ip(); }; }; typedef boost::multi_index_container< HostPtr, boost::multi_index::indexed_by< boost::multi_index::ordered_unique<giveip>, boost::multi_index::random_access<> > > HostSet; typedef HostSet::nth_index<0>::type HostSetOrderedIndex; typedef HostSet::nth_index<1>::type HostSetRandomIndex; Now inserting and accessing elements compiles fine, just when I try to erase something... int main(int argc, char **argv) { HostSet s; HostPtr p1(new Host(boost::asio::ip::address::from_string("127.0.0.1"))); HostPtr p2(new Host(boost::asio::ip::address::from_string("10.10.55.1"))); // now place a pointer to that host in the multiset. HostSetOrderedIndex &oi = s.get<0>(); oi.insert(p1); oi.insert(p2); oi.erase(p1); // booom } Basically, I want the index to access each ptr's ip() function to get the key rather than the ptr itself, which would be just random mem as far as I understand it. So the key extractor should work, shouldn't it? I also tried the lthost() function: typedef boost::multi_index_container< HostPtr, boost::multi_index::indexed_by< boost::multi_index::ordered_unique<boost::multi_index::identity<HostPtr>, lthost>, boost::multi_index::random_access<> > > But that doesn't work either. I guess it's accessing the HostPtr directly instead of dereferencing it. It does compile and also does the job but tests have shown that when I do this: HostSetOrderedIndex &oi = s.get<0>(); oi.insert(p2); HostSetRandomIndex &hsri = s.get<1>(); hsri.sort(); and then iterate over the container (hsri) the order will vary. Sometimes one of the hosts appears at [0] sometimes the other. I'm quite puzzled how this is supposed to work. Can you give me some hints?? Thanks a lot, Stephan PS: I know, the use case is kinda weird. Basically, I want to be able to insert elements with the set logic, and only the IP shall count as identity. Access via random access index is necessary to do hashing in a stable deterministic way over the container.

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Re: [Boost-users] [review][constrained_value] Review of Constrained Value Library begins today
by Robert Kawulak 04 Dec '08

04 Dec '08

Hi Jesse, From: "Jesse Perla" >4. If it is true in general, then this statement: >http://student.agh.edu.pl/~kawulak/constrained_value/constrained_value/ >rationale.html#constrained_value.rationale.no_floats >makes this library practically useless. This is the problem of limited usefulness of built-in floating point arithmetic rather than of this library. If you need constrained floats, use a library for reliable, repeatable floating-point computations. >typedef bounded<double> interest_rate; >interest_rate r1, r2; >change_bounds(r1, .8, .99); > >Now the interest rate bounds on r2 don't exist, right? This is a big >problem for me... It would mean that the bounds information is not kept on >the type, but on the instantiation... Sorry, but this makes no sense to me in the context of constrained values. If the current bounds are [0, 1] and you have r1 == .5 and r2 == .9, then what changing the bounds for the whole type to [.8, .99] would mean for r1? How the type is supposed to know that there is an instance that is not valid according to the new bounds? The type should keep handles to all its instances? Or the bounds should change anyway, leaving the instance in invalid state? So what would be the point of bounds checking, if you can't guarantee that once you assign a valid value then the object will remain valid? >6) Is there any way to get the library to compile: std::max(2, i) instead of >using i.value() as mentioned in the tutorial for a constrained i? No. These are just the rules for template functions. Implicit conversions are not taken into consideration in such case, so both the arguments have to be of identical type. >This >really is essential to make the library equivalent to normal operations, but >with extra type information. Again, I am willing to forgo ease of use on >the bounds checking for this... What I really want is the instantiation to >behave EXACTLY the same as an underlying type. So overloading the ++, +, >etc. are useful, but I would go further to say that perhaps everything could >be done by just going back to the underlying type... What you ask for is not possible in C++. You cannot have one type and use it exactly the same way as other type. I'll give you some examples (having constrained<string> cs): const char * s = cs.c_str(); // not possible Type constrained<string> can't have members that string has. char c = cs[0]; // not possible Type constrained<string> can't have operators that string has. How would you define such operator for constrained class template? How would you know what should be its return type in general case (without decltype available, of course)? Best regards, Robert

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another LNK2019 error
by Joseph A. Marks 04 Dec '08

04 Dec '08

error LNK2019: unresolved external symbol "class boost::unit_test::test_suite * __cdecl init_unit_test_suite(int,char * * const)" (?init_unit_test_suite@@YAPAVtest_suite@unit_test@boost@@HQAPAD@Z) referenced in function _main This is one of those "second order" calls where I cannot even readily find where the call is made to the above function. Is anyone else experiencing LNK2019 errors with Boost (esp. w.r.t. VS 2008) -- see below? Although I received one or two responses to the question posted below, in general, dealing with these linker errros is *MUCH* more difficult than dealing with compiler erros, and there is very little information to go on. Thanks in Advance! (-: Joseph > Subject: LNK2019 with boost::thread_group [!] > To: boost-users(a)lists.boost.org > Date: Monday, December 1, 2008, 11:59 AM > Here is what I'm trying to do: > > boost::thread_group threadGroup; > > for( ; port_min <= port_max; ++port_min ) > { > threadGroup.add_thread(new > boost::thread(boost::bind(CCUThread, port_min, strategy))); > } > > I am getting the following error: > > error LNK2001: unresolved external symbol "void > __cdecl boost::assertion_failed(char const *,char const > *,char const *,long)" > (?assertion_failed@boost@@YAXPBD00J@Z) > ..\bin\ccu_simulator.exe : fatal error LNK1120: 1 > unresolved externals > > Is this Boost-related? > > I found one posting that was somewhat similar on the web, > but the user found an error elsewhere, and it shed no light > on the situation. > > I am also getting several other LNK1120 errors that may be > related to Boost. > > I am converting working VS 6.0 (and occasionally 2005) code > to VS 2008; this has caused this link error to appear. > > I also have changed Boost from v. 1.31 to 1.36; whether > this affects the above linker errors I do not know. > > Any help would be appreciated. > > Last time I posted about a linking error, I received no > replies at all, so if someone knows something, please reply. > > Thanks Again! > > (-: > > Sincerely, > Joseph >

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recording member function calls with the calls' arguments
by Hicham Mouline 04 Dec '08

04 Dec '08

Hello, Is there any library that allows non-intrusively to record calls to member functions of existing classes as well as the arguments of the calls? It seems to be possible to do this with the decorator pattern. Regards,

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how to serialize a const class_name *object
by niranjan bangera 04 Dec '08

04 Dec '08

hi all, Am new to boost serialization concept. here i want to serialize these classes please help me to do this; i tried doing this but am gettin some compile time errors while serializing the object1, Please help me to do this, Boost version am using: 1_36_0 c++ compiler: GCC 4.1.1 (gnu-gcc-4.1.1-binutils-2.16.1/x86_64-pc-linux2.4/bin/gcc) Please help me to solve this simple concept.. Thanks in advance, Nina struct mystruct { const char * name; const char * name2; int number; } class my_class { private: const mustruct * object1 }

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Re: [Boost-users] polymorphic archive use and memory leak
by sam p 04 Dec '08

04 Dec '08

Thanks Guys! I verified your analysis by adding virtual destructor to polymorphic oarchive and mem leak vanished as expected. Currently due to some constraints I cannot move to boost 1.36. In that case, do you think it's sufficient to just add these virtual destructors ? Or there are some other significant fixes related to serialization which also need to be merged from 1.35 code base? -Sameer On 12/3/08, Kim Barrett <kab.conundrums(a)verizon.net> wrote: > > At 10:42 AM +0530 12/3/08, sam p wrote: > >> But if I modify below given code as given below then it doesn't show any >> memory leak. >> I am using boost 1.32. >> > > The virtual destructor for polymorphic_oarchive (and iarchive) was added > relatively recently, I think in boost 1.35. > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[boost.build] should we not define _SECURE_SCL=0 by default for all msvc toolsets
by Thorsten Ottosen 04 Dec '08

04 Dec '08

Dear all, Is there are reason why we do not compile with this flag set by default? Are there any users of Boost out there which actually wants the securuty mode turned on? If not, then I suggest that we change the build settings. Thanks in advance -Thorsten

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[boost::ublas] Question on compressed_matrix
by Bastian Sdorra 04 Dec '08

04 Dec '08

Hello everybody, I have a question on ublas::compressed_matrix. I need to build a submatrix of a compressed_matrix. This should also be a compressed_matrix composed out of different rows of the original matrix. I have a std::set containing all row-indicis of the original matrix rows the submatrix should contain. Here is my problem, I can't find a way to do this. I know that there is a way to get rows out of a matrix. But these are dense rows -> too much unneeded data (Is there a way to insert complete rows at all?). Is there a way to copy a row of a compressed_matrix as compressed_vector and insert the vector in another compressed_matrix? I also thought about extracting only the values!=0 of the individual rows like here: http://guwi17.de/ublas/matrix_sparse_usage.html but I don't want to iterate over all rows and test if the set contains the rowindex. It would be very nice, if someone could give me a hint how to solve this problem. Thanks and regards Bastian

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Unable to use boost libraries with xcode 3.1
by framebuffer 04 Dec '08

04 Dec '08

Hi! I am using xcode 3.1 and I am trying to build a 32bit boost test application. I have done this successfully on windows (Header only libraries are working fine in xcode). These are the steps I followed: 1) ./configure --with-libraries=date_time,filesystem,iostreams,program_options,serialization,system,thread 2) sudo make install I dont get any error and the installation says it updated all targets. 3) Next, I create a simple thread application to test: #include <boost/thread/thread.hpp> #include <iostream> void hello() { std::cout <<"Hello world, I'm a thread!"<< std::endl; } int main(int argc, char* argv[]) { boost::thread myThread(&hello); myThread.join(); return 0; } 4) I go to project > edit project settings and add the following two paths in the search path section: /usr/local/lib (for library path) and /usr/local/include/boost-1_37 for header path. BOOST_ROOT is set as /Users/Framebuffer/boost_1_37_0 I have even tried to change it to /usr/local/ but the errors persist I have examined the two folders and the libraries and headers are indeed present there (for eg, libboost_thread-xgcc40-mt-1_37.dylib is in the lib folder) 5) When I try to compile either the debug or release version, I get errors. Here are the errors for debug build results: ========================================== ========================================== Building target “boost” of project “boost” with configuration “Debug” — (9 errors) Checking Dependencies cd /Users/framebuffer/Desktop/boost /Developer/usr/bin/gcc-4.0 -x c++ -arch i386 -fmessage-length=0 -pipe -Wno-trigraphs -fpascal-strings -fasm-blocks -O0 -Wreturn-type -Wunused-variable -D_GLIBCXX_DEBUG=1 -D_GLIBCXX_DEBUG_PEDANTIC=1 -isysroot /Developer/SDKs/MacOSX10.5.sdk -mfix-and-continue -fvisibility-inlines-hidden -mmacosx-version-min=10.5 -gdwarf-2 -iquote /Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/boost-generated-files.hmap -I/Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/boost-own-target-headers.hmap -I/Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/boost-all-target-headers.hmap -iquote /Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/boost-project-headers.hmap -F/Users/framebuffer/Desktop/boost/build/Debug -I/Users/framebuffer/Desktop/boost/build/Debug/include -I/usr/local/include/boost-1_37 -I/Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/DerivedSources -c /Users/framebuffer/Desktop/boost/main.cpp -o /Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/Objects-normal/i386/main.o cd /Users/framebuffer/Desktop/boost /Developer/usr/bin/g++-4.0 -arch i386 -isysroot /Developer/SDKs/MacOSX10.5.sdk -L/Users/framebuffer/Desktop/boost/build/Debug -L/Developer/SDKs/MacOSX10.5.sdk/usr/local/lib -F/Users/framebuffer/Desktop/boost/build/Debug -filelist /Users/framebuffer/Desktop/boost/build/boost.build/Debug/boost.build/Objects-normal/i386/boost.LinkFileList -mmacosx-version-min=10.5 -o /Users/framebuffer/Desktop/boost/build/Debug/boost Undefined symbols: "boost::thread::join()", referenced from: _main in main.o "boost::thread::~thread()", referenced from: _main in main.o _main in main.o "boost::thread_resource_error::thread_resource_error()", referenced from: boost::mutex::mutex()in main.o boost::condition_variable::condition_variable()in main.o "vtable for boost::detail::thread_data_base", referenced from: __ZTVN5boost6detail16thread_data_baseE$non_lazy_ptr in main.o "typeinfo for boost::thread_resource_error", referenced from: __ZTIN5boost21thread_resource_errorE$non_lazy_ptr in main.o "boost::thread::start_thread()", referenced from: boost::thread::thread<void (*)()>(void (*)(), boost::disable_if<boost::is_convertible<void (*&)(), boost::detail::thread_move_t<void (*)()> >, boost::thread::dummy*>::type)in main.o "boost::detail::thread_data_base::~thread_data_base()", referenced from: boost::detail::thread_data<void (*)()>::~thread_data()in main.o boost::detail::thread_data<void (*)()>::~thread_data()in main.o "boost::thread_resource_error::~thread_resource_error()", referenced from: __ZN5boost21thread_resource_errorD1Ev$non_lazy_ptr in main.o "typeinfo for boost::detail::thread_data_base", referenced from: typeinfo for boost::detail::thread_data<void (*)()>in main.o ld: symbol(s) not found collect2: ld returned 1 exit status "boost::thread::join()", referenced from: _main in main.o "boost::thread::~thread()", referenced from: _main in main.o _main in main.o "boost::thread_resource_error::thread_resource_error()", referenced from: boost::mutex::mutex()in main.o boost::condition_variable::condition_variable()in main.o "vtable for boost::detail::thread_data_base", referenced from: __ZTVN5boost6detail16thread_data_baseE$non_lazy_ptr in main.o "typeinfo for boost::thread_resource_error", referenced from: __ZTIN5boost21thread_resource_errorE$non_lazy_ptr in main.o "boost::thread::start_thread()", referenced from: boost::thread::thread<void (*)()>(void (*)(), boost::disable_if<boost::is_convertible<void (*&)(), boost::detail::thread_move_t<void (*)()> >, boost::thread::dummy*>::type)in main.o "boost::detail::thread_data_base::~thread_data_base()", referenced from: boost::detail::thread_data<void (*)()>::~thread_data()in main.o boost::detail::thread_data<void (*)()>::~thread_data()in main.o "boost::thread_resource_error::~thread_resource_error()", referenced from: __ZN5boost21thread_resource_errorD1Ev$non_lazy_ptr in main.o "typeinfo for boost::detail::thread_data_base", referenced from: typeinfo for boost::detail::thread_data<void (*)()>in main.o ld: symbol(s) not found collect2: ld returned 1 exit status Build failed (9 errors) ========================================== ========================================== Both files libboost_thread-xgcc40-mt-1_37.dylib and libboost_thread-xgcc40-mt-1_37.a are present in /usr/local/lib What am I missing? Any help will be appreciated. ALSO, I tried to compile and run a date time example, and it seems to be working fine. (Both debug and release) Below is the code that is working. Other libraries like filesystem etc and not working though. #include "boost/date_time/gregorian/gregorian.hpp" #include "boost/date_time/posix_time/posix_time.hpp" #include <iostream> using namespace boost::gregorian; using namespace boost::posix_time; int main() { date d(2002,Feb,1); //an arbitrary date ptime t1(d, hours(5)+milliseconds(100)); //date + time of day offset ptime t2 = t1 - minutes(4)+seconds(2); ptime now = second_clock::local_time(); //use the clock date today = now.date(); //Get the date part out of the time date tomorrow = today + date_duration(1); ptime tomorrow_start(tomorrow); //midnight //input streaming std::stringstream ss("2004-Jan-1 05:21:33.20"); ss >> t2; //starting at current time iterator adds by one hour time_iterator titr(now,hours(1)); for (; titr < tomorrow_start; ++titr) { std::cout << (*titr) << std::endl; } return 0; } I found this tutorial : http://soulstorm-creations.com/PROJECT_SOULSTORM_2_0/index.php?option=com_c… and I tried his method and its giving the same 9 errors out of the box. Thanks, fb. -- View this message in context: http://www.nabble.com/Unable-to-use-boost-libraries-with-xcode-3.1-tp208270… Sent from the Boost - Users mailing list archive at Nabble.com.

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boost asio async_read_some
by Chris Freehill 04 Dec '08

04 Dec '08

Hi, I've been struggling for a while trying to get async_read_some() to call the handler I provided, but it never seems to happen. However, the buffer provided does seem to be written with the expected data from the tcp/ip socket I'm using. Here's a simplified version of my call and handler: unsigned char tmpBuffer[512]; //global void MyClass::handler(const boost::system::error_code& error, size_t bytes_transferred) { boost::system::error_code e; std::cerr << "handler called()" << "\n"; } void MyClass::test() { ... socketPtr->async_read_some(boost::asio::buffer(tmpBuffer, 512), boost::bind(&MyClass::handler, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } Can anyone give me any idea as to how I can get my handler to be called? The other thing worth mentioning is that if I use read_some() instead, I get the expected data. In the documentation for this method (see link below), http://www.boost.org/doc/libs/1_37_0/doc/html/boost_asio/reference/basic_st… there is the comment "Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using boost::asio::io_service::post()." I'm not sure exactly what this means...what is this equivalent manner that is mentioned? Thanks, Chris

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