July 2004 - Boost-users - lists.preview.boost.org

thread and Mac OS X
by Tristan King 07 Jul '04

07 Jul '04

i've written a little test to see if i've installed boost properly on my mac #include <boost/thread.hpp> #include <boost/shared_ptr.hpp> #include <boost/bind.hpp> #include <iostream> void simple_thread( boost::shared_ptr<int> p ) { std::cout << (*p) << std::endl; } int main (int argc, char * const argv[]) { boost::thread_group threads; for ( int i = 0 ; i < 5 ; i++ ) { boost::shared_ptr<int> p( new int(i) ); threads.create_thread( boost::bind( &simple_thread, p ) ); } threads.join_all( ); return 0; } in xcode (a C++ Tool project) this compiles fine, however on runtime i get the following error: ZeroLink: unknown symbol '__ZN5boost12thread_groupC1Ev' boost_test has exited due to signal 6 (SIGABRT). using g++ i get the following errors (ignoring warnings) g++ main.cpp -o boost_test -I/usr/local/include/boost-1_31 -L/usr/local/lib ld: Undefined symbols: boost::thread_group::create_thread(boost::function0<void, std::allocator<boost::function_base> > const&) boost::thread_group::join_all() boost::thread_group::thread_group[in-charge]() boost::thread_group::~thread_group [in-charge]() i originally built boost using the command line sudo bjam -sTOOLS=darwin install can anyone help me with what i am missing here? thanks --Tristan

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RE: [Boost-users] [pool] Speed of pool_allocator<>
by Klaus Nowikow 06 Jul '04

06 Jul '04

Peter Dimov wrote: > Klaus Nowikow wrote: > > template <class Allocator> > > double Test() > > { > > std::vector<Allocator::value_type, Allocator> Vector; > > boost::timer Timer; > > > > for(int i = 0; i < NUM_ELEMENTS; ++i) > > { > > Vector.push_back(i); > > } > > > > return Timer.elapsed(); > > } > > If I read the code correctly, you don't create or delete > objects. You create > and delete (large) arrays of objects. I changed the test program (see below). Now I use object_pool<> to create and destroy a number of elements (I use a vector<C*> to store them in the meantime). The results are even worse than before: new/delete: 0.08s object_pool: 25.20s Note that I created a class non_pool with an interface similar to object_pool to be able to use one function template for both tests. // MemoryPoolTest.cpp #include <boost/timer.hpp> #include <boost/pool/object_pool.hpp> #include <vector> #include <iostream> enum { NUM_ELEMENTS = 100000 , CHUNK_SIZE = NUM_ELEMENTS }; class C { int i_; char c_; }; struct Empty { }; template <class T, class U = Empty> struct non_pool // create, destroy with new and delete { explicit non_pool(int) { } T* construct() const { return new T; } void destroy(T* pT) { delete pT; } }; template <template <class, class> class Pool> double Test() { Pool<C> P(CHUNK_SIZE); boost::timer Timer; std::vector<C*> V; for(int i = 0; i < NUM_ELEMENTS; ++i) { V.push_back(P.construct()); } for(std::vector<C*>::iterator pos = V.begin(), end = V.end(); pos != end; ++pos) { P.destroy(*pos); } return Timer.elapsed(); } int main(int, char**) { std::cout << "Starting memory pool test" << std::endl; double Time; std::cout << "Allocating with new : "; Time = Test<non_pool>(); std::cout << Time << "s" << std::endl; std::cout << "Allocating with boost::object_pool<>: "; Time = Test<boost::object_pool>(); std::cout << Time << "s" << std::endl; return 0; }

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errors building boost on Mac OS X
by Tristan King 06 Jul '04

06 Jul '04

Hi, i get a few errors when building the following libraries on Mac OS X 10.3.4 libboost_test_exec_monitor libboost_unit_test_framework i'm building using bjam, and the following command line bjam -sTOOLS-darwin install sniplets of the errors are as follows: darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_prg_exec_monitor-d-1_31.dylib ld: Undefined symbols: cpp_main(int, char**) .... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_test_exec_monitor-d-1_31.dylib ld: Undefined symbols: test_main(int, char**) .... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_unit_test_framework.dylib/darwin/debug/shared-linkable-true/libboost_unit_test_framework-d-1_31.dylib ld: Undefined symbols: init_unit_test_suite(int, char**) am i missing something here? thanks --Tristan

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Problem using exported C++ functions to python
by mayankg＠iiitb.ac.in 06 Jul '04

06 Jul '04

Hi, I have the following type of functions in a class say "MyClass", which I have exported to python. 1) func1(long *plong) 2) func2(TempClass **pptempclass) (where TempClass is some other class) Now, I exported these using the following: .def("func1", &MyClass::func1) .def("func2", &MyClass::func2) and it compiled well. But now when I try to use them in a python script, I have no clue as to how I create and pass: 1) a long pointer as argument to func1 2) a double pointer to TempClass as argument to func2 How do I achieve this behaviour? 1) Do I have to wrap the above functions> If yes, then how? How will they be used in python then? OR 2) I can still use the same functions in python but then how to create (instantiate and initialize) the above pointers in python? Thanks, Mayank

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RE: [Boost-users] Re: detect unneded includes
by Ben Hutchings 05 Jul '04

05 Jul '04

Adrian Stoica <adrian_stoica(a)btinternet.com> wrote: > I'm not aware of any such tools, but it could be done with a Perl > script that removes the includes one at a time, and then invokes the > compiler. If the file compiles ok, it's probably safe to remove that > include. No, unfortunately not. A header might appear to be redundant because it is included by another, yet this may be a mere implementation detail which is subject to change and should not be relied upon. In the absence of a true module system this is impossible to determine. Also it could be that the header defines template specialisations, or macros with the same names as functions/objects. Removing such a header might not make the program ill-formed but could still break it subtly. Instantiating a template in one translation unit for the same template arguments for which there is an explicit specialisation in another translation unit results in undefined behaviour. With sufficient testing you can *probably* avoid such mishaps but I would be very wary of trying to automate this.

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newbie: need example (call python from c++)
by Peter Piehler 04 Jul '04

04 Jul '04

Hello, I use call<void>(pyFunc,arg1,..) to call a python function with standard double, int etc. What must I do to call a function with a c++ object as argument? psydocode: class MyAnimal { /*...*/ std::string __strName; public: MyAnimal() : __strName("Tux") {} /*...*/ std::string getName() { return __strName;} void setName(const std::string &strName) { __strName = strName; } }; int main() { /*...*/ MyAnimal* pTux = new Animal; /*do something with pTux*/ /*use a python function with pTux*/ call<void>(pyFunc1, ?pTux? ); /*change attributes pTux in pyFunc2*/ dog = call<MyAnimal>(pyFunc2, ?pTux?); /*if it possible to call by reference?*/ call<void>(pyFunc3, ?pTux?); pTux->getName();// return Cat } python module: def py_func1(a): print a.getName() def py_func2(a): a.setName('Dog') return a def py_funnc3(a): a.setName('Cat') ___________________________________________________________ Gesendet von Yahoo! Mail - Jetzt mit 100MB Speicher kostenlos - Hier anmelden: http://mail.yahoo.de

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Problem with boost random library.
by Joshua Little 04 Jul '04

04 Jul '04

Hi all, I'm trying to use the randome number generators but I am having some problems. I'm using boost 1.31.0 and gcc 3.2 on Windows 2000. Here is my code : printf(" Die \n "); //std::cout << "Die Rolls" << std::endl; try { boost::mt19937 rng; // produces randomness out of thin air // see pseudo-random number generators boost::uniform_int<> six(1,6); // distribution that maps to 1..6 // see random number distributions boost::variate_generator<boost::mt19937, boost::uniform_int<> > die(rng, six); // glues randomness with mapping int x = die(); printf(" Die %d\n ",x); } catch(...) { std::cout << "exception" << std::endl; printf(" Die exception \n "); } I basically copied the example code off the web site to see if I could get it to work but I'm not having any luck. If I have the variate_generator defined as above I do not not get any output to the console after the declaration of die. I tried printf's and stream output but neither works, I never see the "Die %d" printed out and I do not see either of the outputs in the catch(...) section. printed either. I even had a throw in the try block at one time to see if it could get to the catch section and did not see output. When I remove the die declaration (and comment out the code that uses it) but leave the generator and the distribution then I can see output again and if I throw after the distribution declaration then I see both output statements in the catch block. So it seems like if I have the variate generator declared then I can't see any output after that, but when I comment it out I can see output again. I'm not sure what I'm doing wrong since I am basically copying a pretty simple example from the book I just can't get it to work. Ah and just incase this makes a difference I'm running this code as a test case in a boost test suite. I wanted to try to get it to work there before putting it into my main app. Thanks, Joshua.

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building boost program options
by Christopher Baus 03 Jul '04

03 Jul '04

I'm trying to build the boost sandbox project program_options and am failing. Anyone know what version of boost is compiles cleanly with? -- Christopher Baus http://www.baus.net/

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RE: [Boost-users] Re: boost test doesn't track validation outside autofunctions
by Rozental, Gennadiy 02 Jul '04

02 Jul '04

> > > void validate(X args) { > > > if (some tests) > > > BOOST_ERROR("message"); > > > } > > > BOOST_AUTO_UNIT_TEST(testfunction) { > > > // set up arguments > > > validate(args) > > > } [...] > I think the problem is a think-o on my part. > In the pseudo-code above, BOOST_ERROR is not executed unless > "some tests" is true. So if the tests are OK, BOOST_ERROR is > never hit. > > I think the report of 0 (boost) tests being run is therefore > accurate, though confusing. It should actually say that 1 test cases being run, but no assertions executed. > Does that sound right? > > Is there a way to signal to boost that you are doing a test, > without the error? You have 2 choices. 1. Rewrite your test, so that it looks like: ... BOOST_CHECK_MESSAGE( some_test, "message" ); 2. Or you could write it like this: .... If(some_test) BOOST_ERROR("message") else BOOST_MESSAGE( "no error" ); I prefer first solution usually. HTH, Gennadiy

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boost test doesn't track validation outside auto functions
by Ross Boylan 02 Jul '04

02 Jul '04

I have a test program that looks like this, in stylized form: -------------------------- #include <boost/test/auto_unit_test.hpp> using namespace boost::unit_test_framework; void validate(X args) { if (some tests) BOOST_ERROR("message"); } BOOST_AUTO_UNIT_TEST(testfunction) { // set up arguments validate(args) } ---------------------------------- When I run this with report-level detailed, it reports that there are 0 assertions in testfunction. Furthermore, the assertions done in validate are not even added to the overall number of assertions reported for the run. I know the checks are being run, because I have seen errors from them. Also, the error messages include the name "testfunction", so it is available at run time. It would be nice if the error reporting and logging functions got their info at run-time; apparently they are grabbing it from some pre-processor magic at the moment (I haven't examined the code in detail; that's just an inference from the behavior). Since the tests do seem to be run, this is basically a cosmetic problem, but it would be nice to fix. If any easy fixes occur to anyone, I'd love to know. Boost 1.31.0 on Debian. P.S. The module's author is listed as rogeeff(a)fusemail.com in the documentation, but that address doesn't work. -- Ross Boylan wk: (415) 502-4031 530 Parnassus Avenue (Library) rm 115-4 ross(a)biostat.ucsf.edu Dept of Epidemiology and Biostatistics fax: (415) 476-9856 University of California, San Francisco San Francisco, CA 94143-0840 hm: (415) 550-1062

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