May 2008 - Boost-users - lists.boost.org

[boost.function] evaluating needed arguments only
by Olaf Krzikalla 02 Jun '08

02 Jun '08

Hi, is it possible to check a function bound to boost::function, if a particular argument is actually needed? Example: ---- struct bar {}; typedef boost::function<void(int, bar&)> tSlot; void foo(tSlot& s); void barNeeded(int, bar&); void barNeeded(int); void callfoo() { foo(boost::bind(&barNeeded, _1, _2)); foo(boost::bind(&barNotNeeded, _1)); } void foo(tSlot& s) { bar b; expensive_calculation(b); s(1, b); } ---- How can I prevent expensive_calculation if the function barNotNeeded was bound to tSlot? Best regards Olaf Krzikalla

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[Test] Documentation confusion
by Maik Beckmann 02 Jun '08

02 Jun '08

Hello, I am confused about the boost.test documentation. There are docs in trunk and after some hours of digging via gmane if found this one http://www.patmedia.net/~rogeeff/html/index.html index.html in trunk : ... Revised: 28 February, 2006 index.html external link: Copyright © 2001-2007 Gennadiy Rozental ... My impression is that the 2007 version is much more comprehensive. Why isn't the most recent one in trunk? Do the trunk docs got a link the the external docs? -- Maik

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Boost.Test: missing include file
by Jarl Friis 02 Jun '08

02 Jun '08

I am using BOOST_CHECK_CLOSE which is defined in test_tools.hpp. I my test I have #include <boost/test/unit_test.hpp> Aparently this requires that I also include #include <boost/test/floating_point_comparison.hpp> wouldn't it be more correct to have this include in the test_tools.hpp file? Jarl

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Test tree is empty
by Stephen Torri 02 Jun '08

02 Jun '08

I am sure this is a silly common answer but I am not sure how to resolve it. Here is my test suite below. I am following http://www.hpfsc.de/boosttest/ as my guide. #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE Statistical algorithm test suite #include <boost/test/unit_test.hpp> #include "Statistical_Test.h" using boost::unit_test_framework::test_suite; using boost::unit_test_framework::test_case; using namespace libreverse::classifier; class statistical_test_suite : public test_suite { public: statistical_test_suite () : test_suite ( "statistical_test_suite" ) { // create an instance of the test cases class boost::shared_ptr<Statistical_Test> instance ( new Statistical_Test() ); test_case* test_Constructor_test_case = BOOST_CLASS_TEST_CASE( &Statistical_Test::test_Constructor, instance ); add ( test_Constructor_test_case ); } }; test_suite* init_unit_test_suite ( int, char** ) { test_suite* top_test_suite = BOOST_TEST_SUITE("Statistical algorithm test suite"); // add test suites to the top test suite top_test_suite->add ( new statistical_test_suite() ); return top_test_suite; }

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variant<> number of template arguments
by Hicham Mouline 01 Jun '08

01 Jun '08

Hello, I have a use of the visitor pattern (this was an answer provided to me on c++-moderated) as shown below. Question1: is the maximum number of variant<> arguments extendable? Question2: Below, some of the variants I have are full template specs. Is there a way to write the variant<> typedef with templates instead and have the operator() of the static visitor a template member. Rds, --------------- #include <iostream> #include <boost/variant.hpp> struct derived1 {}; struct derived2 {}; struct derived3 {}; typedef boost::variant<derived1, derived2, derived3> base; // function object struct operation : boost::static_visitor<int> { int operator()(const derived1&) const { return 1; } int operator()(const derived2&) const { return 2; } int operator()(const derived3&) const { return 3; } }; int main() { base a = derived1(); operation op; std::cout << a.apply_visitor(op) << std::endl; // prints "1" base a = derived2(); std::cout << a.apply_visitor(op) << std::endl; // prints "2" }

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Trouble building statecharts with gcc 4.3.0
by Abhinandan Jain 01 Jun '08

01 Jun '08

Hi I am having trouble compiling boost statechart code using gcc 4.3.0. I tried this on the +sample program on statechart site and get the same errors. The errors are of the type error: value-initialization of reference for each process_event call in the example: myWatch.process_event( EvStartStop() ); myWatch.process_event( EvStartStop() ); myWatch.process_event( EvStartStop() ); Does anyone have a suggestion on how to fix this? Thanks Abhi

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How to open a file with its associated application?
by Zdravko Monov 01 Jun '08

01 Jun '08

Hi! Is there a C++ library that can, given a filename, start the default application for its type to open it? -- Zdravko Monov

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Re: [Boost-users] Boost-users Digest, Vol 1645, Issue 3
by Fox Fossati 31 May '08

31 May '08

Message: 8 Date: Wed, 28 May 2008 09:18:22 +0900 From: "Kurata Sayuri" <magicalsayuri(a)gmail.com> Subject: Re: [Boost-users] Visual C++ 2008- from system::String to boost::any ? To: boost-users(a)lists.boost.org Message-ID: <b09a4ea0805271718vffa0c18m2d2565947fd159e0(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 On Wed, May 28, 2008 at 12:19 AM, Fox Fossati <stonfofish(a)yahoo.it> wrote: > Excuse me, > I' m reading a DataGridView with VisualC++2008 with nested loops.... > ..... > Object^ val=dataGridView1[x,y]->Value; //Object is a Visual class > ..... > I convert every value in a System::String variable: > String^ str=val->ToString(); > > Then I'have to insert this data in a container (for example) this: > vector<boost::any>* vec=new vector<boost::any>(n) ; > //0<=x<n > (*vec)[x]=str; //ERROR! > (*vec)[x]=*str; //ERROR! > > Is there another method to transfer a value from a dataGridView to an STL > container? > Now i wrote only a vector to explain simply but in fact i will use a table > of this type vector<vector<boost:.any>*>. Your code is C++/CLI. So, you can use System::Object instead of boost::any. And also, cliext::vector instead of std::vector. Because native class (such as boost::any, std::vector) can't have managed instance. ---- #include <cliext/vector> Object^ val = dataGridView1[x,y]->Value; String^ str = val->ToString(); cliext::vector<Object^>^ vec = gcnew cliext::vector<Object^>(n) ; // or cliext::vector<String^> (*vec)[x]=str; ------------------------------ Is it possible to convert a System::String to an std:string? With a conversion then i can use my boost classes...but i need to convert from std::string to System::String and vice versa.... I should use visual c++ only for interface input/output unless using visual classes....do you think i will have a lot of troubles? It's very difficult to find a good ide rad.... Thanks a lot! ___________________________________ Scopri il Blog di Yahoo! Mail: trucchi, novità, consigli... e la tua opinione! http://www.ymailblogit.com/blog/

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[multi_array] how to modify the dimension of an array?
by r0d 31 May '08

31 May '08

Hello everybody, i'm looking for the best way to modify the dimensions of an array. For example, i got this one: boost::multi_array<int, 2> array ( boost::extents[3][3] ); and i want to change it in an array of 5 dimensions. Now, what i'm doing is to create a new array of 5 dimensions and copying the first one into it, then delete the first one. But i'm sure that a more efficient way exists. No? -- View this message in context: http://www.nabble.com/-multi_array--how-to-modify-the-dimension-of-an-array… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] Problems using pre-compiled boost libraries with Visual Studio 2005
by Trigve Siver 31 May '08

31 May '08

Hi, > From: "Fanara, Mark A (GE Infra, Transportation)" <Mark.Fanara(a)ge.com> > > I downloaded the current pre-built boost library files, but am having > some difficulty with them. > ... > > Next error message received is "This application has failed to start > because the application configuration is incorrect. Review the manifest > file for possible errors. Reinstalling the application may fix this > problem. For more details, please see the application event log." > > ... Do you have VS 2005 SP1 installed ? I think that precompiled packages are built on 2005 SP1 Trigve

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