[Boost-users] sub_range, assign and permutation_iterator related problem

22 Feb 2007

      Hi,
  It is an extension to one my previous post, where I needed help while 
giving access to a sub_range for of an container.
In that problem , Mr Thorsten Ottosen, provided answer to all of my 
queries (Many thanks to him ).

This time I am interested to provide indexed access to a vector with a 
sub_range ,using permutation_iterator.
Here some codes are creating problem, while I am using sub_range with 
permutation iterator.

To specify, I am providing a small test code.
typedef std::pair<std::size_t,std::size_t> pair_t;
template<typename T>
class vector_e : private std::vector<T>{
public:	
	typedef vector_e<T> self_type;
	typedef typename std::vector<T>::iterator iterator;
	typedef typename std::vector<T>::const_iterator const_iterator;
	typedef boost::sub_range<self_type> range;
	typedef boost::sub_range<const self_type> const_range;
	typedef typename std::vector<T>::size_type size_type;
	typedef std::vector<int> index_type;
	typedef typename boost::permutation_iterator<typename 
iterator,index_type::const_iterator> index_iterator;
	typedef typename boost::permutation_iterator<typename 
const_iterator,index_type::const_iterator> const_index_iterator;
	vector_e() : std::vector<T>(){}
	using std::vector<T>::begin;
	using std::vector<T>::end;
	using std::vector<T>::operator [];
	using std::vector<T>::insert;
	index_iterator begin_i(const index_type& i){
		return boost::make_permutation_iterator(begin(),i.begin());
	}
	const_index_iterator begin_i(const index_type& i)const{
     return boost::make_permutation_iterator(begin(),i.begin());
	}

	index_iterator end_i(const index_type& i){
	 return boost::make_permutation_iterator(begin(),i.end());
	}
	const_index_iterator end_i(const index_type& i)const{
		return boost::make_permutation_iterator(begin(),i.end());
	}
	range get_range(const pair_t& range){
		return 
boost::make_iterator_range(begin()+range.first,begin()+range.second);
	}
	const_range get_range(const pair_t& range)const{
		return 
boost::make_iterator_range(begin()+range.first,begin()+range.second);
	}
	range get_range(const index_type& i){
		return 
boost::make_iterator_range(boost::make_permutation_iterator(begin(),i.begin()),
			boost::make_permutation_iterator(begin(),i.end()));
	}
};
int main(int argc,char** argv) {
	using namespace boost;
	using namespace boost::assign;
	using namespace boost::lambda;
	using boost::lambda::_1;
	typedef vector_e<int> elem_t;
	typedef std::vector<int> index_t;
	elem_t v;
	int a[] = {00,10,20,30,40,50,60,70,80,90,100};
	v.insert(v.end(),a,a+11);	
	const elem_t& cv = const_cast<elem_t&>(v);
	//v+= 00,10,20,30,40,50,60,70,80,90,100;	
	std::cout<<"original array : ";
   std::for_each(v.begin(),v.end(),std::cout<<_1<<" ");
///For continuous ranges.
	elem_t::range r = v.get_range(std::make_pair(1,5));
	std::cout<<std::endl<<" range (1,5) : ";
///working fine
	std::for_each(r.begin(),r.end(),std::cout<<_1<<" ");
///working fine
	elem_t::const_range cr = v.get_range(std::make_pair(1,5));
	std::cout<<std::endl<<" c_range (1,5) : ";
	std::for_each(cr.begin(),cr.end(),std::cout<<_1<<" ");
///working fine
   elem_t::const_range cr1 = cv.get_range(std::make_pair(1,5));
	std::cout<<std::endl<<" c_range1 (1,5) : ";
	std::for_each(cr1.begin(),cr1.end(),std::cout<<_1<<" ");

   index_t i;
	i+=0,2,6,4,9;
	std::cout<<std::endl<<" index : ";
	std::for_each(i.begin(),i.end(),std::cout<<_1<<" ");
	std::cout<<std::endl<<"index range ";
//working fine
	std::for_each(v.begin_i(i),v.end_i(i),std::cout<<_1 << " ");
	std::cout<<std::endl<<"c index range ";
///working fine
	std::for_each(cv.begin_i(i),cv.end_i(i),std::cout<<_1 << " ");
///not working (and its const counter part )
	elem_t::range ir = v.get_range(i);
}
The error it is giving in visual studio 7.1 for sub_range of 
permutation_iterator is,
E:\boost_1_33_1\boost\range\iterator_range.hpp(60): error C2440: 'type 
cast' : cannot convert from 'boost::range_iterator<C>::type' to 
'boost::range_iterator<C>::type'
         with
         [
             C=const boost::iterator_range<vector_e<int>::index_iterator>
         ]
         and
         [
             C=vector_e<int>::self_type
         ]

The questions are
1) Can anyone point out the problem ? (Is sub_range is typed by iterator 
by any chance, or typed by container only ? )
2) This is aux question. How to make assign library work for my 
inherited container (vector_e here ), like the commented line ?

any help is appreciated, and thanks to the community .

abir

-- 
Abir Basak, Member IEEE
Software Engineer, Read Ink Technologies
B. Tech, IIT Kharagpur
email: abir@abirbasak.com
homepage: www.abirbasak.com

[Boost-users] sub_range, assign and permutation_iterator related problem

abir basak