September 2004 - Boost-users

question about ublas
by yanyaqin 03 Sep '04

03 Sep '04

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Re:[Boost-users] Re: There's someone using boost lu_substitute?
by yanyaqin 03 Sep '04

03 Sep '04

2 1

Does ublas::lu_* use the character of sparse_matrix/compressed_matrix?
by yanyaqin 02 Sep '04

02 Sep '04

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exec_mon_example.cpp
by Steven T. Hatton 02 Sep '04

02 Sep '04

On SuSE Linux 9.1 using both my own build of boost 1.31, and SuSE provided rpms, as well as both my own build of gcc 3.3.3 and the one from SuSE, I was not able to build this file found in the boost source tree boost_1_31_0/libs/test/example/exec_mon_example.cpp It can also be found here: http://www.boost.org/libs/test/example/exec_mon_example.cpp This is what happens: $ g++ -o exec exec_mon_example.cpp /tmp/ccGtnzc0.o(.text+0x107): In function `main': : undefined reference to `boost::execution_monitor::execute(bool, int)' collect2: ld returned 1 exit status I've also tried variation of the following: g++ -o exec exec_mon_example.cpp -L /org/boost/lib -l \ boost_test_exec_monitor-gcc /opt/org/boost/lib/libboost_test_exec_monitor-gcc.so: undefined reference to `test_main(int, char**)' collect2: ld returned 1 exit status Does this compile for other Linux users? Any suggestions? -- Regards, Steven

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boost::bind questions
by Matt S Trentini 02 Sep '04

02 Sep '04

Heya Boosters, I ran into a problem using boost::bind yesterday and, although I found a workaround, I've got a few questions. For the record I'm using boost 1.30. I stumbled onto the issue that boost::bind doesn't define the argument_type typedef (I was trying to use std::not1). After trawling the web I found a discussion, and useful workaround, about this here: http://tinyurl.com/5bl9m Questions that arose from this: o Why doesn't boost::bind support argument_type? o What other standard library function adapters does this affect? - Is it all that are derived from unary_function? o Has the operator! addition been incorporated into later versions of boost? - If not, why not? Thanks! Matt

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There's someone using boost lu_substitute?
by yanyaqin 02 Sep '04

02 Sep '04

Hi folks, I'm ready to use boost lu_substitute for solving sparse symmetric linear equation, but the document for lu.hpp is almost none. Is there someone could provide me a real number demo? Best regards! Yan Yaqin 2004-09-02 ========================== 263电子邮件－信赖邮自专业

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ublas aix test failures
by Daniel Elliott 02 Sep '04

02 Sep '04

Hello, I am interested in using ublas for a large government project. I noticed ublas (as of 8-19-2004) failed test3 on the visual age c++ compiler. What does this test exercise? We have currently installed the 1.31 libraries. Is this the same code that produced the test results? Thank you for your time. Sincerely, Dan Elliott --------------------------------- Do you Yahoo!? Win 1 of 4,000 free domain names from Yahoo! Enter now.

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Preprocessor lib question wrt to vertical repetition
by Allen Gooch 01 Sep '04

01 Sep '04

Given the following #include <boost/preprocessor/repetition/enum_params.hpp> #ifndef TYPELIST_MAX_SIZE # define TYPELIST_MAX_SIZE 7 #endif template <BOOST_PP_ENUM_PARAMS(TYPELIST_MAX_SIZE, class T)> class ObjectImpl : BOOST_PP_ENUM_PARAMS(TYPELIST_MAX_SIZE, public T), public ObjectBase<REFCNTR> { public: virtual Refcount acquire() const { return Base::acquire(); } virtual Refcount release() const { return Base::release(); } virtual Refcount getRefcount() const { return Base::getRefcount(); } virtual bool hasInterface(InterfaceID const & iid) const { return Base::hasInterface(iid); } virtual IObject * getInterface(InterfaceID const & iid) { IObject const * const_this = (IObject const *) this; return (IObject *) const_this->getInterface(iid); } virtual IObject const * getInterface(InterfaceID const & iid) { IObject const * obj = 0; switch (iid) { case IObject::IID : { this->acquire(); obj = static_cast<IObject const *>(this); break; } // Desired: for each type T in typelist generate the following case block // case T::IID : // { // this->acquire(); // obj = static_cast<T const *>(this); // break; // } default : { throw InterfaceUnsupportedException(iid) break } } return obj; } protected: ObjectImpl() { } virtual ~ObjectImpl() { } typedef ObjectBase<REFCNTR> Base; }; What is the best way to generate a case block for each type in the typelist? I've been looking at the Preprocessor appendix from the "C++ Template Metaprogramming" book (can't wait!) and see three different approaches to vertical repetition: local, file and self; however, I'm not clean on how to express what I want using these approaches. Can someone shed some light, or point me to an example in the Boost PP docs which solves a similar problem? Many thanks in advance. -allen

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Another lambda question
by Maximilian Wilson 01 Sep '04

01 Sep '04

I am getting another compiler error when trying to use the lambda library. Current experiment is string extraction. I'm trying to create a lambda(x) that pushes any char passed to it onto a particular string. string s2; void (std::string::*ft)(char) = &std::string::push_back; // extract function pointer because push_back is overloaded char c = 'n'; bind<void>(ft, var(s2), _1, 1)(c); // should push one 'n' onto the string. However, it doesn't compile bind<void>(reinterpret_cast<char(std::string::*)(char)>(ft), var(s2), _1, 1)(c); // error messages made me think it might be because push_back returns void // I know this isn't good practice, but I'm just trying to figure out what's wrong // However, this won't compile either. And then I get this error /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/actions.hpp:109: error: no matching function for call to `boost::lambda::function_adaptor<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*)(char)>::apply(char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const&)(char), std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, char&, const int&)' I'm not really sure what the real problem is. Can you tell from looking at the error message what I should be doing? Thanks in advance Max Wilson (FULL ERROR TEXT FOLLOWS) /usr/include/boost/lambda/detail/actions.hpp: In static member function `static RET boost::lambda::function_action<4, T>::apply(A1&, A2&, A3&, A4&) [with RET = void, A1 = char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), A2 = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, A3 = char, A4 = const int, T = void]': /usr/include/boost/lambda/detail/lambda_functor_base.hpp:442: instantiated from `RET boost::lambda::lambda_functor_base<boost::lambda::action<4, Act>, Args>::call(A&, B&, C&, Env&) const [with RET = void, A = char, B = const boost::tuples::null_type, C = const boost::tuples::null_type, Env = const boost::tuples::null_type, Act = boost::lambda::function_action<4, void>, Args = boost::tuples::tuple<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), const boost::lambda::lambda_functor<boost::lambda::identity<std::string&> >, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]' /usr/include/boost/lambda/detail/lambda_functors.hpp:151: instantiated from `typename T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type boost::lambda::lambda_functor<Base>::operator()(A&) const [with A = char, T = boost::lambda::lambda_functor_base<boost::lambda::action<4, boost::lambda::function_action<4, void> >, boost::tuples::tuple<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), const boost::lambda::lambda_functor<boost::lambda::identity<std::string&> >, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >]' proj1.cpp:180: instantiated from here /usr/include/boost/lambda/detail/actions.hpp:109: error: no matching function for call to `boost::lambda::function_adaptor<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*)(char)>::apply(char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const&)(char), std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, char&, const int&)' /usr/include/boost/lambda/detail/actions.hpp:109: error: return-statement with a value, in function declared with a void return type bash-2.05b$ g++ proj1.cpp -I /users/user2/ugrad/m/mdw45/boost_1_31_0 /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/actions.hpp: In static member function `static RET boost::lambda::function_action<4, T>::apply(A1&, A2&, A3&, A4&) [with RET = void, A1 = char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), A2 = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, A3 = char, A4 = const int, T = void]': /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/lambda_functor_base.hpp:442: instantiated from `RET boost::lambda::lambda_functor_base<boost::lambda::action<4, Act>, Args>::call(A&, B&, C&, Env&) const [with RET = void, A = char, B = const boost::tuples::null_type, C = const boost::tuples::null_type, Env = const boost::tuples::null_type, Act = boost::lambda::function_action<4, void>, Args = boost::tuples::tuple<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), const boost::lambda::lambda_functor<boost::lambda::identity<std::string&> >, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]' /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/lambda_functors.hpp:151: instantiated from `typename T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type boost::lambda::lambda_functor<Base>::operator()(A&) const [with A = char, T = boost::lambda::lambda_functor_base<boost::lambda::action<4, boost::lambda::function_action<4, void> >, boost::tuples::tuple<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const)(char), const boost::lambda::lambda_functor<boost::lambda::identity<std::string&> >, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, const int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >]' proj1.cpp:180: instantiated from here /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/actions.hpp:109: error: no matching function for call to `boost::lambda::function_adaptor<char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*)(char)>::apply(char (std::basic_string<char, std::char_traits<char>, std::allocator<char> >::*const&)(char), std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, char&, const int&)' /users/user2/ugrad/m/mdw45/boost_1_31_0/boost/lambda/detail/actions.hpp:109: error: return-statement with a value, in function declared with a void return type -- Sometimes I think decisions through, weigh the consequences, decide it is not a good idea, but blind myself and make it anyway. I do not think this is a good thing to do, but it might be. Humans are endowed with both reason and emotion for a reason. -Tara Greenwood

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boost::graph adding verticies and edges whilst performing a dfs
by Daren Grant 01 Sep '04

01 Sep '04

Greetings all , I have a quick question regarding the boost graph library and depth first search operations. I have a very large graph , which has a visitor attached to the depth_first_search routine. The Visitor may add in more verticies / Edges when visiting an existing vertex in the Graph. (NOTE :: All the added verticies / edges from the visitor are guaranteed to be higher in the graph structure! i.e. the DFS algorithm would not have processed them at time of insertion. ) My question is can the depth_first_search handle changes to the Graph whilst it is performing its operation ? From my observations of the colour map used I dont think this is possible with the core depth_first_search routine in the library , could someone confirm this , and if anyone has ideas on how this can be performed I would be most grateful to hear their thoughts !

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Guidelines for effective exception usage
by Stephen torri 31 Aug '04

31 Aug '04

Are there any guidelines on where and when to use exceptions? Are there any boost components that deal with exceptions? Stephen -- Email: storri(a)torri.org

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