Re: [Boost-users] boost python noobie questions

From: chun ping wang (cablepuff_at_[hidden])
Date: 2006-08-05 03:11:40

heres the definition file..

mediandef.hpp

it includes <boost/lambda/lambda.hpp>

template <typename T,
         template <typename ELEM,typename = std::allocator<ELEM> >
         class CONT
 >
 T select(const CONT<T>& a,
          typename CONT<T>::iterator k,
          typename CONT<T>::iterator left,
          typename CONT<T>::iterator right)
 {
         using namespace boost::lambda;
         typedef typename CONT<T>::iterator iter;
         while (true)
         {
          // iter q(random_partition(a, left, right, k));
          iter q(std::stable_partition(left, right, _1 < *k));
          if (k == q)
             return *q;
          else
          {
              (k < q) ? right = --q : left = ++q;
          }
         }
 }

 C:\cs classes\cs512b\c++\def\mediandef.hpp In function `T select(const
CONT<T, std::allocator<_CharT> >&, typename CONT<T, std::allocator<_CharT>
>::iterator, typename CONT<T, std::allocator<_CharT> >::iterator, typename
CONT<T, std::allocator<_CharT> >::iterator)':
269 C:\cs classes\cs512b\c++\def\mediandef.hpp `_1' undeclared (first use
this function)

i fix the other stuff... also i have a basic question.. how do you compile
boost.python..

assuming your using dev-cpp inside c:\dev-cpp folder and your boost folder
is in c:\boost_1_33_1...

On 8/3/06, François Duranleau <duranlef_at_[hidden]> wrote:
>
> On Thu, 3 Aug 2006, chun ping wang wrote:
>
> > Hey I have several problem...
> >
> > A.) Can boost::python work with templated argument...
> >
> > Example:
> >
> > template <class T>
> > boost::tuple<T, T, T> boost::rsa_generate(const T& p, const T& q)
> > {
> [snip]
> > }
> >
> > BOOST_PYTHON_MODULE(rsa)
> > {
> >   def("rsa_generate", boost::rsa_generate);
> > }
>
> [and]
>
> > Second question.. how come lambda function don't work.
> >
> > COmpling this by itself..give no error.
> >
> > template <class T,
> >        template <typename ELEM,
> >                 typename = std::allocator<ELEM> >
> >                 class CONT>
> > double MyAnn::getCondProb(const T& A, const T& B, const CONT<typename
> > std::pair<T, T> >& DATA)
> > {
> [snip]
> > }
> >
> > now including this file.. and compling  this gives error about "_1"
> >
> > BOOST_PYTHON_MODULE(bayesian)
> > {
> >   def ("getCondProb", getCondProb<long long>);
> > }
>
> For both def, you need to specify all template arguments. You can't take
> the address of a function template otherwise. You need to decide which
> instantiations to export.
>
> As for _1, what's the reported error? Could it be a namespace problem?
>
> --
> François Duranleau
> LIGUM, Université de Montréal
>
> "Quand le dernier arbre sera abattu, la dernière rivière empoisonnée,
>   le dernier poisson capturé, alors seulement vous vous apercevrez que
>   l'argent ne se mange pas."
>                                                - Prophétie d'un Indien
> Cree
>     (cité par Marlo Morgan dans _Message des hommes vrais au monde
> mutant_)
>
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