April 2006 - Boost-users - lists.boost.org

Using boost::lambda::bind with std::transform
by Kobi Cohen-Arazi 27 Apr '06

27 Apr '06

Hi, Would like to do the following with boost::lambda::bind #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <algorithm> using namespace boost::lambda; struct Foo{ std::string get(){ ... } }; std::vector<Foo> array; // say it is already populated std::vector<std::string> tr; // the transformed instead using my handcrafted for loop, I would like to transform the std::list<Foo>::iterator endIter=array.end (); for (std::list<Foo>::iterator iter=array.begin(); iter!=endIter ;++iter) { noExtResults.push_back (iter.get().replace (0,5, "")); } I know it should be something like: std::transform (array.begin(), array.end (), std::back_inserter(tr), bind(&Foo::get, _1)); So here I'm stuck. The bind function will know to extract the string using get. But how to I get that string and do something like: bind(&std::string::replace (???)) Thanks in advance for your kind help, Kobi.

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[algorithm - strings] problems with borland c++ 6
by Federico Feller 27 Apr '06

27 Apr '06

Hi, Im having problems using the string algorithm of boost with Borland C++ 6.0. Precisely, I cant compile the sequence.cpp because of the following error: [C++ Error] sequence.hpp(186): E2285 Could not find a match for 'boost::algorithm::detail::replace<InputT,ForwardIteratorT>(StringE,char *,char *,undefined,undefined)' Iam using std::string for string algorithms. Any ideas? Thanks, Federico __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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[checked_delete] pimpl with scoped_ptr<T>
by Herve Alexanian 27 Apr '06

27 Apr '06

Hello, This is my first post regarding boost, I hope I am sending it to the right list. I have a question regarding the use of scoped_ptr versus shared_ptr: I am trying to use scoped_ptr<Impl> to implement the "Pimpl" idiom in order to hide the Impl definition from the user. Since my class is not copyable I thought using a scoped_ptr was better suited than a shared_ptr. So, something like this: class Impl; class MyClass { scoped_ptr<Impl> m_pImpl; ... ... }; When compiling client code, I see a checked_delete error. Reading the blurb about checked_delete this makes sense to me and I am able to work around the error by putting an explicit destructor declaration in MyClass. But, I don't see any error if I use a smart_ptr instead of a scoped_ptr. Why is the requirement about not deleting an incomplete type any different between scoped_ptr and shared_ptr? Thanks, Herve Alexanian Sonics, inc.

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[mpl] no result_type defined
by Frank Birbacher 27 Apr '06

27 Apr '06

Hi! I want to create a container of pointers to objects in a range (first,last(. I tried to use mpl, but have been without success. I understand, that the lambda "&_1" cannot specify its concrete return type, so I added ret<T>(...). But the resulting lambda is rejected by the make_transform_iterator function. I'm using boost 1.33.0 on gcc 4.0.2 //****** CODE BEGIN ****** #include <vector> #include <iterator> #include <boost/iterator/transform_iterator.hpp> #include <boost/lambda/lambda.hpp> template<typename Iterator> void foo(Iterator first, Iterator last) { using boost::make_transform_iterator; using namespace boost::lambda; typedef typename std::iterator_traits<Iterator>::pointer Pointer; std::vector<Pointer> objectPointers( make_transform_iterator(first, ret<Pointer>(&_1)), make_transform_iterator(last, ret<Pointer>(&_1)) ); // ... } int main() { std::vector<int> v; //instantiate template: foo(v.begin(), v.end()); } //***** CODE END ****** // ** ERROR on GCC 4.0.2: ** /mnt/daten/develop/boost/boost/iterator/transform_iterator.hpp:43: Fehler: kein Typ namens »result_type« in »class boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::explicit_return_type_action<int*>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::other_action<boost::lambda::addressof_action>, boost::tuples::tuple<boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, 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> > >, 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> > >« The error says it cannot find the type "result_type" in "class ....". What is wrong here? Frank

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[BGL] How to build graphviz with MS VC8?
by Rui Carvalho 27 Apr '06

27 Apr '06

Hi, I'm trying to build graphviz so as to be able to use read_graphviz in the boost graph library. My understanding is that the make file in Boost 1_33_1\boost_1_33_1\libs\graph\src is not yet ready for VC -but I may be missing something obvious here. Is there a simple way to compile the graphviz library with VC? Thanks, Rui

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Boost::program_options - Linking Issue
by Adam Hartshorne 27 Apr '06

27 Apr '06

Using the following command lines on a linux box, g++ -c -pipe -Wall -W -O2 -pipe -m64 -fexceptions -D_REENTRANT -DQT_NO_DEBUG -DQT_THREAD_SUPPORT -DQT_SHARED -I/usr/lib64/qt-3.3/mkspecs/default -I. -Idcs/improc2/adam/boost_1_33_1/ -I/usr/lib64/qt-3.3/include -I.moc/ -o .obj/first.o first.cpp g++ -o cmdLineTest .obj/first.o -L/usr/lib64/qt-3.3/lib -L/usr/X11R6/lib64 -L/dcs/improc2/adam/boost_1_33_1/stage/lib/ -lboost_program_options-gcc -lqt-mt -lXext -lX11 -lm -lpthread I get the following error output when trying to compile the first.cpp example provided with the library .obj/first.o(.text+0x57): In function `main': : undefined reference to `boost::program_options::options_description::options_description(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' .obj/first.o(.gnu.linkonce.t._ZNK5boost15program_options25basic_command_line_parserIcE3runEv+0x5): In function `boost::program_options::basic_command_line_parser<char>::run() const': : undefined reference to `boost::program_options::common_command_line_parser::run() const' .obj/first.o(.gnu.linkonce.t._ZN5boost15program_options25basic_command_line_parserIcEC1EiPPc+0x42): In function `boost::program_options::basic_command_line_parser<char>::basic_command_line_parser(int, char**)': : undefined reference to `boost::program_options::common_command_line_parser::common_command_line_parser(std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&)' And help would be greatly appreciated, Adam

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[1.33.1][mpl] increasing BOOST_MPL_LIMIT_LIST_SIZE doesn't work
by Marc Mutz 27 Apr '06

27 Apr '06

Hi, According to the mpl docs, defining above macro to e.g. 30 should make boost::mpl::list<> take 30 template arguments, and thus enable boost::variant<> to hold 21 different types (default: 20 on my platform (gcc 4.0)). Yet compiling the attached sample program gives me attached error message, which indicates that mpl::list<> still takes only 20 template parameters. Bug? Thanks, Marc -- Marc Mutz -- marc(a)klaralvdalens-datakonsult.se, mutz(a)kde.org Klarälvdalens Datakonsult AB, Platform-independent software solutions

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I/O bug in date_time
by Thomas Lemaire 27 Apr '06

27 Apr '06

Dear list, I encounter a bug while reading a time_duration object, here is a short test case, the results are obtained with boost 1.33.1, gcc4.0.3 using namespace boost::posix_time; time_duration td1(0,0,0); std::stringstream ss1("14:23:11.345678"); ss1 >> td1; std::cout << td1 << std::endl; // 14:23:11.345678 time_duration td2(0,0,0); std::stringstream ss2("18353:23:11.345678"); ss2 >> td2; std::cout << td2 << std::endl; // 18:53:23 time_duration td3(0,0,0); std::stringstream ss3("318353:23:11.345678"); ss3 >> td3; std::cout << td3 << std::endl; // 00:00:00 If I compile with the flag CPPFLAGS += -DUSE_DATE_TIME_PRE_1_33_FACET_IO this is working well. I hope this will help to fix it... -- thomas http://www.laas.fr/~tlemaire

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any and Map
by Joe McCay 27 Apr '06

27 Apr '06

if dt=3.5; is a double, then would dt=3.5F; be a float? and dt=3.5L; would be a long double? I had forgotten about those. People don't talk & wrtie about thosse much. Would something similar happen with int & long? Joe McCay

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bcbboost 0.4 released
by Nicola Musatti 27 Apr '06

27 Apr '06

Hallo, I just released version 0.4 of bcbboost, a set of patches that enable use of the Boost 1.33.1 libraries with Borland's BCB2006. This release is the first to support the bcc32 5.8.2 compiler, which comes with Update2. You can download it from here: http://prdownloads.sourceforge.net/bcbboost/bcbboost-1_33_1-5_8_2-0.4.zip?d… Please post any bug report, suggestion, request for clarification to the project trackers on its SourceForge site: http://sourceforge.net/projects/bcbboost/ Cheers, Nicola Musatti

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