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pimpl and boost
by David Gruener 29 Apr '05

29 Apr '05

Hi, i'm wondering if there is a nice smart pointer in boost to implement PImpl. I found an implementation here: [1]. So, does boost provide a smart pointer which does play nice with pimpl, so that one doesn't need to provide a destructor, copyconstructor and assignment operator for the default cases? --David [1] http://www.octopull.demon.co.uk/arglib/TheGrin.html.

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redefinition of `class boost::algorithm::iterator_range<IteratorT>'
by Michael Garriss 28 Apr '05

28 Apr '05

this program: #include <boost/algorithm/string.hpp> #include <boost/range.hpp> produces this error: In file included from /home/mgarriss/dev/tp-compiled/include/boost-1_32_0/boost/range.hpp:20, from range.cxx:2: /home/mgarriss/dev/tp-compiled/include/boost-1_32_0/boost/range/iterator_range.hpp:79: error: redefinition of `class boost::algorithm::iterator_range<IteratorT>' /home/mgarriss/dev/tp-compiled/include/boost-1_32_0/boost/algorithm/string/iterator_range.hpp:50: error: previous definition of `class boost::algorithm::iterator_range<IteratorT>' /home/mgarriss/dev/tp-compiled/include/boost-1_32_0/boost/range/iterator_range.hpp:380: error: `template<class IteratorT> boost::algorithm::iterator_range<IteratorT> boost::make_iterator_range(IteratorT, IteratorT)' conflicts with previous using declaration `template<class IteratorT> boost::algorithm::iterator_range<IteratorT> boost::algorithm::make_iterator_range(IteratorT, IteratorT)'

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bgl question: in which namespace to put the functions
by Andreas Fabri 28 Apr '05

28 Apr '05

Hello, Developping code so that BGL algorithms can run on the vertices and edges of CGAL triangulations, I am wondering if there are rules or recommendations for in which namespace the functions source, target, vertices, out_edges ... shall go. In boost, because it is boostish code, or in CGAL, because that is the namespace where the triangulation lives in? thank's in advance, andreas

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Re: pimpl and boost
by Gottlob Frege 28 Apr '05

28 Apr '05

> Today's Topics: > > 1. Re: pimpl and boost (Gennadiy Rozental) > 2. Re: Re: Re: pimpl and boost (David Gruener) > 3. Re: Re: Re: pimpl and boost (Jeff Flinn) > > ---------------------------------------------------------------------- > I so wish that pimpl was somehow part of the language. ie you don't worry about or see the pointer at all, nor do you have to forward all the function calls. I don't see why the compiler couldn't implement pimpl for me. (Of course, for cases where you want multiple implementations at run time, etc, you still do that yourself, but the typical case the compiler could do). Maybe: // h file class Foo interface { void GetX(); }; // cpp file: class Foo continue // some keyword { int x; }; Foo::GetX() { return x; } And just like implementing the same function twice, the linker could warn about 2 implementations of the same class. P.S. this could also allow you to keep some members defined in the h file, (and others in the cpp impl) if you wanted the speed of inlines for some variables, or public/protected variables, etc. Just a thought. Maybe I should complain elsewhere...

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Program_options and XML
by Jason Stewart 28 Apr '05

28 Apr '05

Has anyone implemented an XML parser for boost::program_options? I have just started looking into using this library but I need to read/write XML files. Before digging in and doing it myself I thought I'd ask if anyone has looked at the problem. Thanks, Jason Stewart

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BGL::johnson_all_pairs_shortest_path question
by Andreas Fabri 28 Apr '05

28 Apr '05

Hello, What is the non-named parameter version of this algorithm. In the online manual it says Weight (and this is probably a typo, as there is a template parameter WeightMap). Also what are the arguments id1 and zero good for? andreas

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[BGL] check edge existence in adjacency_matrix in constant time?
by Felipe Magno de Almeida 28 Apr '05

28 Apr '05

Sorry if I have overlooked something in the docs, but Im really not finding it... Is there someway to check the existence of an edge in adjacency_matrix in constant time knowing its vertices? An explanation or a pointer to the right place in the docs would be really appreciated. Thanks in advance, -- Felipe Magno de Almeida UIN: 2113442 email: felipe.almeida at ic unicamp br, felipe.m.almeida at gmail com, felipe at synergy com I am a C, modern C++, MFC, ODBC, Windows Services, MAPI developer from synergy, and Computer Science student from State University of Campinas(UNICAMP). To know more about: Unicamp: http://www.ic.unicamp.br Synergy: http://www.synergy.com.br current work: http://www.mintercept.com "There is no dark side of the moon really. Matter of fact it's all dark."

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Re: [Boost-users] Compatibility between shared_ptr and Rational RoseRT
by Dave.Ware＠seleniacomms.com 28 Apr '05

28 Apr '05

Don't worry about having hijacked my original thread. The examples you've been discussing have been very helpful to my code as well. We haven't solved all of our problems yet, but it is much better. Thanks ------------------------------------------------------------ This email and any attached files contains company confidential information which may be legally privileged. It is intended only for the person(s) or entity to which it is addressed and solely for the purposes set forth therein. If you are not the intended recipient or have received this email in error please notify the sender by return, delete it from your system and destroy any local copies. It is strictly forbidden to use the information in this email including any attachment or part thereof including copying, disclosing, distributing, amending or using for any other purpose. In addition the sender excludes all liabilities (whether tortious or common law) for damage or breach arising or related to this email including but not limited to viruses and libel.

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Function pointers, result_of<> and function_traits<>
by Delfin Rojas 27 Apr '05

27 Apr '05

Hello all, I am trying to get the return type of a member function given its signature. Consider the following example from the boost result_of test: struct X {}; int main { using namespace boost; typedef int (X::*mem_func_ptr)(float); BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr(X,char)>::type, int>::value)); } This test compiles/runs with no problems. Now, what I want is the return type of a function with signature "int (X::*)()" I added the following to the test: typedef int (X::*empty_mem_func_ptr)(); BOOST_STATIC_ASSERT((is_same<result_of<empty_mem_func_ptr(X)>::type, int>::value)); This does not compile. I get an error boost_1_32_0\boost\utility\result_of.hpp(43) : error C2825: 'F::template': cannot form a qualified name. I tried to do this same thing with function_traits but it seems function traits does not support member function pointers at all. So this is all I have. If somebody can help me I would appreciate it. Thanks -delfin

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const-correctness and lambda expression
by Matthias Kaeppler 27 Apr '05

27 Apr '05

Hi, in my program, I have this function to compute the sum of sizes of a bunch of files: Glib::ustring DirBrowser::get_total_file_size() { using namespace boostfs; // boostfs = boost::filesystem using namespace lambda; // lambda = boost::lambda boost::intmax_t sum = 0; std::for_each(m_first_file,m_files.end(),sum+=bind(&file_size,*_1)); return make_size_human_readable( sum ); } The line with for_each computes the sum of file sizes, by iterating over a container of pointers to boostfs::pathS, starting at the first file (there are also directories, before the files), till the end, invoking the lambda functor on each. Since this method does not change the state of the object, I wanted to declare it const, but suddenly the lambda expression starts complaining: Somehow, those path objects inside the lambda expression become const now, too, and it doesn't compile anymore. How come? -- Matthias Kaeppler

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