September 2003 - Boost-users

how to create fixtures in unit test framework
by Anders Moe 03 Sep '03

03 Sep '03

Hi all. The boost unit test framework seems to lack the xUnit buildUp/tearDown (whatever) methods meant to faciliate the creation of fixtures. Does that mean there is an alternative idiom to achieve the same effect ? Constructing new class-test-cases for each test seems a bit overkill. Regards, Anders.

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Lambda operator= question
by Rodolfo Lima 02 Sep '03

02 Sep '03

Hi people, That's the first time I'm using lambda and I'm stuck with something that can be resumed to: struct A { int Test() { return 0; } }; int x; A a; (var(x)=bind(&A::Test,_1))(a); In other words, I want to make a functor that calls a member function and stores its return value in some variable. I'm compiling with VC7.1 and it returns error C2440: '=' : cannot convert from 'const boost::tuples::cons<HT,TT>::stored_head_type' to 'int' Is there something I can do to get rid of this error and compile successfully? I'm appending the whole compiler output in the end of the post. Thanks, rod //--------- Whole compiler output c:\RodSoft\lib\boost\boost\lambda\detail\operator_lambda_func_base.hpp(242) : error C2440: '=' : cannot convert from 'const boost::tuples::cons<HT,TT>::stored_head_type' to 'int' with [ HT=const boost::lambda::detail::parameter_traits_<const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>,const boost::lambda::detail::IF<false,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>> &,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>>::RET>::type, TT=boost::tuples::detail::map_tuple_to_cons<boost::tuples::null_type,boost:: tuples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::t uples::null_type,boost::tuples::null_type,boost::tuples::null_type,boost::tu ples::null_type,boost::tuples::null_type,boost::tuples::null_type>::type ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called c:\RodSoft\lib\boost\boost\lambda\detail\lambda_functors.hpp(153) : see reference to function template instantiation 'RET boost::lambda::lambda_functor_base<Act,Args>::call<boost::lambda::lambda_fun ctor_base<Act,Args>::sig<SigArgs>::type,A,const boost::tuples::null_type,const boost::tuples::null_type,const boost::tuples::null_type>(A &,B &,C &,Env &) const' being compiled with [ RET=boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::la mbda::assignment_action>,boost::tuples::tuple<boost::lambda::lambda_functor< boost::lambda::identity<int &>>,const boost::lambda::detail::parameter_traits_<const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>,const boost::lambda::detail::IF<false,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>> &,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>>::RET>::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::t uples::null_type>>::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, Act=boost::lambda::other_action<boost::lambda::assignment_action>, Args=boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::ident ity<int &>>,const boost::lambda::detail::parameter_traits_<const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>,const boost::lambda::detail::IF<false,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>> &,const boost::_bi::bind_t<int,boost::_mfi::mf 0<int,A>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>>::B1>>>::RET> ::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>, SigArgs=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>, A=A, B=const boost::tuples::null_type, C=const boost::tuples::null_type, Env=const boost::tuples::null_type ] c:\RodSoft\pessoal\TstConsole\TstConsole.cpp(49) : see reference to function template instantiation 'boost::lambda::lambda_functor_base<Act,Args>::sig<SigArgs>::type boost::lambda::lambda_functor<T>::operator ()<A>(A &) const' being compiled with [ Act=boost::lambda::other_action<boost::lambda::assignment_action>, Args=boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::ident ity<int &>>,const boost::lambda::detail::parameter_traits_<const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>,const boost::lambda::detail::IF<false,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>> &,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>>::RET>::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::t uples::null_type>, SigArgs=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>, T=boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lamb da::assignment_action>,boost::tuples::tuple<boost::lambda::lambda_functor<bo ost::lambda::identity<int &>>,const boost::lambda::detail::parameter_traits_<const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>,const boost::lambda::detail::IF<false,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>> &,const boost::_bi::bind_t<int,boost::_mfi::mf0<int,A>,boost::_bi::list1<boost::_bi: :list_av_1<boost::arg<1>>::B1>>>::RET>::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_t ype>>, A=A ] Build log was saved at "file://c:\RodSoft\pessoal\TstConsole\Debug\BuildLog.htm" TstConsole - 1 error(s), 0 warning(s)

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CodeWarrior PS2, Boost, & STL
by Yohann DOS SANTOS 02 Sep '03

02 Sep '03

Hello Boost Users, When i try to compile a class that use a vector with CodeWarrior for PS2 R3.03, i have this error message : Error : illegal use of incomplete struc/union/class 'Metrowerks::compile_assert<0>' (instantiating: 'std::vector<int, std::allocator<int>>') (instantiating: 'std::__vector_imp<int, std::allocator<int>, l>') vector line 729 ompile assert<bool(sizeof(T) == sizeof(typename Metrowerks::strore_as<T>;;type))> And just above the error line, in the vector file : // Error : illegal use of incomplete struct/union/class 'Metrowerks::compile_assert<0>' // This means that the store_as table in <msl_utility> is not set correctly. // sizeof(T) == sizeof(typename Metrowerks::store_as<T>::type must be true. The code compiles and works perfectly with VC6 sp5 on PC and XBOX. Thanks for any help.

2 1

[BGL] Adding one graph to another
by Tarjei Knapstad 02 Sep '03

02 Sep '03

I need to add/copy one graph into another, both completely connected, and then create an edge between one vertex in the original graph and a vertex in the one copied into it. The edge/vertex properties needs to be copied as well, and this needs to be fairly efficient. The new edge is straightforward, but is there any functionality for the copy/add operation? (Something like an "add_component" algorithm I guess...) To my understanding both the copy_graph and copy_component algorithms both replace all the content in the target graph. If not, what would be the most efficient way to solve this sort of problem? Cheers, -- Tarjei Knapstad

2 3

spirit list_p example
by Larry 02 Sep '03

02 Sep '03

From boost-1.30.2 I built the list_parser.cpp example using MSVC++7.1. In the CSV list I added ",,2" to the end of the line to be parsed. The program ran but the neither of the added elements were included in the output vector. Having used the tokenizer before I know it will generally gobble up adjacent delimiters without any output. You can get the empty token if you ask for the delimiters as well and then just discard the delimiters (sort of). But I was surprised that the 2 didn't make it to the output vector. I expected the empty list entry would not make the output vector. I tried adding ~anychar_p to the rule but that didn't help. If I change the input list to add ",\"\",2" I get "" and 2 in the output vector. Applications like spreadsheets do not put missing column values for numeric columns as "" items generally. Maybe I am missing something because it certainly isn't the behavior I would expect (either from the parser or the tokenizer).

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adjancency propoerty iterator
by sashan 02 Sep '03

02 Sep '03

Hi Is there an adjancency iterator for property types. You can get an iterator for property types like this: typedef graph_property_iter_range<GraphType, vertex_name_t>::iterator VNameIterator; .... tie(It, ItEnd) = get_property_iter_range(m_Graph, vertex_name); I'd like to know if there is something similar for adjacency iterators. Thanks [Non-text portions of this message have been removed]

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RE: [Boost-Users] Given std::map<ID,struct>, efficient way to access std::vector<struct.member>?
by Sam Partington 01 Sep '03

01 Sep '03

Well, I've trimmed you're example down some more, as to me it didn't seem to be important that the struct was a member of CFilter. So I think your question boils down to : struct A { int a; }; typedef std::map<int, A> my_map; void do_something_on_a_slice(int a) { // whatever } void f(const my_map& map_) { std::for_each(map_.begin(), map_.end(), /*what goes here*/); } You could use iterator_adaptors for this, but I think that is complicating things unnecessarily, something like this would work (untested) : struct select_a : std::unary_function<my_map::value_type, int> { const result_type& operator()(const argument_type& arg) const { return arg.second.a; } // similar non const operator here }; void f(const std::map<int, A>& map_) { boost::projection_iterator_generator<select_a, my_map::const_iterator>::type first(map_.begin()), last(map_.end()); std::for_each(first, last, do_something_on_a_slice); } See http://www.boost.org/libs/utility/projection_iterator.htm But I think bind in this situation is a better solution. (Partly because the interface to iterator_adaptors will be changing in the next release, possibly to the point of breaking the above code - Jeremy?) void f(const my_map& map_) { using boost::bind; std::for_each(map_.begin(), map_.end(), bind(do_something_on_a_slice, bind(&A::a, bind(&my_map::value_type::second, _1) ) ) ); } Though at this point I would consider writing a function object, any expression involving three bind's is getting close to (or some might say past) write-only code. As to efficiency, if this is a bottleneck it is mostly likely the iteration over the map that is causing the problem, or the actual 'doing' code. Most of the binding code should be optimised away by the compiler to a bare mimimum. It may be that you are better changing container, a sorted vector perhaps. HTH Sam (PS Apologies if I did miss a point somewhere and oversimplify your code) Chris Russell <> wrote: > Hello folks, I've got an interesting little design problem > and I'm looking > for some advice on how best to implement an efficient solution. (snip) > Here's a simplified statement of the problem that I believe > outlines the > relevant details: > > I've got a class declared as follows: > > --- begin example class ---- > In English: CFilter declares some structure with some number > of data members > of arbitrary types. Internally CFilter allocates a std::map of these > structures using some key_t. Effectively this defines a table > of data whose > rows are of type sRow_t, and whose columns can be conceptualized as > std::vector<A_t>, std::vector<B_t> where > std::vector<sRow_t.some_member>.size() == mapData<key_t, > sDataRow_t>.size(). > > At runtime, CFilter.ProcessRow is called std::map<key_t, > sRow_t>.size() times followed by a single call to CFilter.ProcessData. > > I'm trying to figure out how to _efficiently_ access the > column vectors in > the implementation of CFilter.ProcessData.

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