June 2010 - Boost-users - lists.boost.org

boost:any/boost::variant for integral/floating type
by Mathieu Malaterre 03 Jun '10

03 Jun '10

Hi, I am looking at boost::any and boost::variant which seems to be very usefull additions to C++ for building heterogenous containers. However in my case I need to build something that would be: - type safe - can only contains integral/floating type - allow operations such as max() / min() My typical operation on this 'generic_value_type' is simply `+= 1`. boost::any seems difficult to use, since you need to call any_cast any time you want to operate on the value. I am thinking I could just wrap boost::variant inside a custom class, and add my missing functionalities, something like: struct AttributeValue { private: struct add_one_visitor : public boost::static_visitor<> { template <typename T> void operator()(T & i) const { i++; } }; struct get_min_visitor : public boost::static_visitor<> { template <typename T> T operator()(T & i) const { return std::numeric_limits<T>::min(); } }; public: AttributeValue& operator++() { boost::apply_visitor( add_one_visitor(), Value ); return *this; } AttributeValue min() { return boost::apply_visitor( get_min_visitor(), Value ); } boost::variant<double, char, int> Value; }; Did I miss anything in boost ? Is boost::variant my best option (when only using fundamental types) ? Thanks -- Mathieu

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boost and nvcc on msvc 9.0
by Prevrhal, Sven 03 Jun '10

03 Jun '10

Something to share - I had difficulties compiling a .cu file with #include <boost/random.hpp> with cuda 3.0 and msvc 9.0 The nvcc compiler first complained about not having stdint.h (true, it's not part of cuda or msvc). I #undef'd BOOST_HAS_STDINT_H in the config/compiler/nvcc.hpp header but then it complained about wrong int limits in base_traits. I figured out that setting #define BOOST_MSVC 1500 makes that error go away. I assume this breaks portability since nvcc.hpp is now locked to msvc but there doesn't seem to be a mechanism for telling boost about the nvcc host compiler. So ugly for now, but it seems to work at least for boost/random There's another problem with my code but it's probably not boost related, that is the mvsc debugger pointer jumps around wildly at some point in the code and then it crashes. In release mode, the program runs fine until the end when it too crashes. If you think you have an idea, I'll post the code. Sven ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

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[BGL] Graph coloring program
by Mike Douglass 03 Jun '10

03 Jun '10

I have uploaded the graph coloring program to http://groups.google.com/group/graph_coloring_program/ go to the files section and download the files and read README. I'm willing to license my code under the Boost license. Opening a track ticket ok.

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Boost MPI
by Miguel Ángel Vázquez 03 Jun '10

03 Jun '10

Dear all, I already installed Boost MPI library and I tested like you suggest in the tutorial (executing bjam in /libs/mpi/test). Unfortunately, it doesn't pass all the tests and I don't know whether they are important or not or what to do to try to fix them. I enclose you the output, hope someone can help me somehow. Cheers, Miguel

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Generalize boost::optional as boost::range to support boost::range::adaptors
by bradphelan＠xtargets.com 03 Jun '10

03 Jun '10

Hi all, I've implemented a small adaptor to make boost::optional behave like a range. This extends the functionality of boost::optional to be more like the scala Option class and the haskell Maybe monad. A trivial motivating example is int plus(const int & i){ return i + 1; } void foo(boost::optional<int> opt_v){ boost::copy ( opt_v | boost::adaptors::transformed(plus) , std::ostream_iterator<int>(std::cout) ); } foo(10) outputs 11 The full implementation and details are at http://xtargets.heroku.com/2010/06/03/using-boostoptional-as-a-range/ Does anybody think this is a useful extension to boost::optional or would be willing to provide feedback or suggestions on the implementation. Regards Brad

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error compiling an accumulator sample
by Conoscenza Silente 03 Jun '10

03 Jun '10

Hi All I cannot build the following sample using accumulators. Do you know why? I used times ago an example and it worked without any problem. Can you help me with that? I have the following error error: ‘covariate1’ was not declared in this scope #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/mean.hpp> #include <boost/accumulators/statistics/moment.hpp> #include <boost/accumulators/statistics/variance.hpp> #include <boost/accumulators/statistics/covariance.hpp> using namespace boost::accumulators; int main() { accumulator_set<double, stats<tag::mean, tag::variance, tag::covariance<double, tag::covariate1> > > x_acc; x_acc( 1.1, covariate1 = 2.2 ) ; return 0; }

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Error:<no tag> cannot be initialized in a constructor.
by Conoscenza Silente 03 Jun '10

03 Jun '10

HI All I am using boost accumulators. These 2 lines use to work fine with current version of boost in LInux. accumulator_set< double, stats< tag::covariance<double, tag::covariate1> > > acc_cov; accumulator_set< double, stats< tag::variance > > acc_var; When I moved to a Sun machine where it is installed boost v1.40 I have this building error "/opt/boost/boost/accumulators/framework/depends_on.hpp", line 276: Error:<no tag> cannot be initialized in a constructor. "/opt/boost/boost/fusion/container/list/cons.hpp", line 85: Where: While instantiating "boost::accumulators::detail::accumulator_wrapper<int, int>::accumulator_wrapper(const boost::accumulators::detail::accumulator_wrapper<int, int>&)". "/opt/boost/boost/fusion/container/list/cons.hpp", line 85: Where: Instantiated from non-template code. 1 Error(s) Do you know how can I fix those errors and why I have this issue? Thanks

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[lambda][phoenix] print expression tree
by alfC 03 Jun '10

03 Jun '10

As you can see from other posts. It's been quite painful to me to debug programs with expression templates. In order to debug some code I implemented some functions to print the expression trees, this would be a nice addition to Boost.Lambda and also to Boost.Phoenix (although Boost.Phoenix will probably have it through Boost.Proto which apparently already can print its expression trees). Here it is a *minimal* code for printing some Boost.Lambda expression (involving only [binary +,-,/,*],bind,constants), (let me know if I am reinventing the wheel) namespace boost{ namespace lambda{ using namespace boost::tuples; template<int N> //print placeholder std::string to_string(const lambda_functor<boost::lambda::placeholder<N> >&){ return "_"+boost::lexical_cast<std::string>(N); } //template<class T> //std::string to_string(const T& t){ // return boost::lexical_cast<std::string>(t); //} //binary operators #define BOOST_LAMBDA_TO_STRING_GEN(action_name, symbol_string)\ template<class LExp1, class LExp2> \ std::string to_string(const \ lambda_functor<lambda_functor_base<arithmetic_action<action_name>, tuple< \ LExp1, \ LExp2 \ > > >& action_name##_expr){ \ return to_string(get<0>(action_name##_expr.args)) + #symbol_string +to_string(get<1>(action_name##_expr.args)); \ } BOOST_LAMBDA_TO_STRING_GEN(plus_action, +); BOOST_LAMBDA_TO_STRING_GEN(divide_action, /); BOOST_LAMBDA_TO_STRING_GEN(minus_action, -); BOOST_LAMBDA_TO_STRING_GEN(multiply_action, *); //bind template<class FunctionType, class LExpr> std::string to_string(const lambda_functor<lambda_functor_base<action<2, function_action<2> >, tuple< FunctionType, //double (* const)(double), LExpr > > >& bind_expr){ return std::string("bind(") +boost::units::detail::demangle(typeid(FunctionType).name()) +", "+to_string(get<1>(bind_expr.args)) + ")"; } }} Cheers, Alfredo

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Re: [Boost-users] issue when building boost with msvc2010
by Christian Henning 03 Jun '10

03 Jun '10

Hi there, I've been building boost with MSVC10 Express just fine. I usually use the Visual Studio Command Prompt window to get things done. Here you can double check if your environment variable "Include" is correct. Inside the command prompt just type "set include". My windows.h is in C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Include which is set inside include path. Regards, Christian On Wed, Jun 2, 2010 at 5:12 PM, Sean Farrow <sean.farrow(a)seanfarrow.co.uk> wrote: > Hi: > > When building boost with msvc 2010, I get a c1083 unable to open file with > windows.h. > > My command line is: > > Bjam –toolset=msvc –stage –build-type=complete > > Even though as the output asks I have called vcvarsall.bat. > > A portion of the log follows: > > compile-c-c++ > bin.v2\libs\test\build\msvc-10.0\debug\asynch-exceptions-on\link-static\runtime-link-static\debug.obj > > debug.cpp > > C:\Program Files\boost\boost/test/impl/debug.ipp(32) : fatal error C1083: > Cannot open include file: 'windows.h': No such file or directory > > > > call "C:\Program Files\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" > x86 >nul > > cl /Zm800 -nologo > @"bin.v2\libs\test\build\msvc-10.0\debug\asynch-exceptions-on\link-static\runtime-link-static\debug.obj.rsp" > > > > ...failed compile-c-c++ > bin.v2\libs\test\build\msvc-10.0\debug\asynch-exceptions-on\link-static\runtime-link-static\debug.obj... > > Anyone got any ideas, do I need to set up some environment variables? > > Vs2008 builds fine with the latest windows sdk, the latest windows sdk > configuration tool doesn’t allow integration with vc2010. > > Help appreciated as always. > > Regards > > Sean. > > Regards > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[spirit] what's wrong with my parser ?
by Kamil Zubair 03 Jun '10

03 Jun '10

I try to make parser for the following string: "value = x" or "value = [x1, x2]" I also want to retrieve the value of x or x1 and x2. My minimum code that will produce error is like this: typedef pair<float, boost::optional<float> > range_val; rule<string::const_iterator, range_val(), locals<float, boost::optional<float> > > range_value; rule<string::const_iterator> valid_line; range_value = (float_[_a = _1] | ("[" >> *space >> float_[_a = _1] >> ',' >> float_[_b = _1] >> *space >> "]"))[_val = boost::phoenix::bind(make_pair<float, boost::optional<float> >, _a, _b)]; valid_line = "value = " << range_value; I'm using vs 2008 with boost 1.43, the above code will produce this error: 1>f:\library\boost_1_41_0\boost\spirit\home\qi\nonterminal\rule.hpp(176) : error C2664: 'boost::mpl::assertion_failed' : cannot convert parameter 1 from 'boost::mpl::failed ************(__thiscall boost::spirit::qi::rule<Iterator>::=::error_invalid_expression::* ***********)(Expr)' to 'boost::mpl::assert<false>::type' 1> with 1> [ 1> Iterator=std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char>>, 1> Expr=boost::proto::exprns_::expr<boost::proto::tag::shift_left,boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal,boost::proto::argsns_::term<const char (&)[9]>,0>,boost::spirit::qi::rule<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char>>,range_val (void),boost::spirit::locals<float,boost::optional<float>>> &>,2> 1> ] 1> No constructor could take the source type, or constructor overload resolution was ambiguous 1> f:\project\experiment\spirit\spirit.cpp(82) : see reference to function template instantiation 'boost::spirit::qi::rule<Iterator> &boost::spirit::qi::rule<Iterator>::operator =<boost::proto::exprns_::expr<Tag,Args,Arity>>(const Expr &)' being compiled 1> with 1> [ 1> Iterator=std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char>>, 1> Tag=boost::proto::tag::shift_left, 1> Args=boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal,boost::proto::argsns_::term<const char (&)[9]>,0>,boost::spirit::qi::rule<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char>>,range_val (void),boost::spirit::locals<float,boost::optional<float>>> &>, 1> Arity=2, 1> Expr=boost::proto::exprns_::expr<boost::proto::tag::shift_left,boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tag::terminal,boost::proto::argsns_::term<const char (&)[9]>,0>,boost::spirit::qi::rule<std::_String_const_iterator<char,std::char_traits<char>,std::allocator<char>>,range_val (void),boost::spirit::locals<float,boost::optional<float>>> &>,2> 1> ] can someone point out what's wrong with my parser ?

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