thrust copy_if with const source - cuda

Question

My problem is in the following code:
The filter function compiles, and runs as it should when the source is not constant (the iterators are adjusted accordingly). However when I change the source to const, the compiler gives me the following error for the first two variables of the copy_if statement:
"the object has type qualifiers that are not compatible with the member function".
I believe there is a const to not const conversion error somewhere but frankly I have no idea where. Any help would be appreciated.
#include "thrust\device_vector.h"
#include "thrust\copy.h"
typedef thrust::device_vector<float>::const_iterator Dc_FloatIterator;
typedef thrust::device_vector<float>::iterator D_FloatIterator;
typedef thrust::device_vector<int>::const_iterator Dc_IntIterator;
typedef thrust::device_vector<int>::iterator D_IntIterator;
typedef thrust::tuple< Dc_IntIterator, Dc_IntIterator, Dc_FloatIterator> Dc_ListIteratorTuple;
typedef thrust::zip_iterator<Dc_ListIteratorTuple> Dc_ListIterator;//type of the class const iterator
typedef thrust::tuple< D_IntIterator, D_IntIterator, D_FloatIterator > D_ListIteratorTuple;
typedef thrust::zip_iterator<D_ListIteratorTuple> D_ListIterator;//type of the class iterator
struct selector{//selector functor for the copy if call
const int val;
selector(int _val) : val(_val) {}
__host__ __device__
bool operator()(const int& x ) {
return ( x == val );
}
};
class Foo{
public:
thrust::device_vector<int> ivec1;
thrust::device_vector<int> ivec2;
thrust::device_vector<float> fvec1;
Foo(){;}
~Foo(){;}
D_ListIterator begin(){//cast of begin iterator
return D_ListIterator(D_ListIteratorTuple( ivec1.begin(), ivec2.begin(), fvec1.begin() ));
}
D_ListIterator end(){//cast of end iterator
return D_ListIterator(D_ListIteratorTuple( ivec1.end(), ivec2.end(), fvec1.end() ));
}
Dc_ListIterator cbegin(){//cast of const begin iterator
return Dc_ListIterator(Dc_ListIteratorTuple( ivec1.cbegin(), ivec2.cbegin(), fvec1.cbegin() ));
}
Dc_ListIterator cend(){//cast of const end iterator
return Dc_ListIterator(Dc_ListIteratorTuple( ivec1.cend(), ivec2.cend(), fvec1.cend() ));
}
void const_filter( const Foo& TheOther, const int& target ){//doesnt work
//This function should copy those member of the vectors where
//the ivec2[i] == target is true
thrust::copy_if(
TheOther.cbegin(),
TheOther.cend(),
TheOther.ivec2.cbegin(),
this->begin(),
selector(target) );
}
void filter( Foo& TheOther, const int& target ){//works
//This function should copy those member of the vectors where
//the ivec2[i] == target is true
thrust::copy_if(
TheOther.begin(),
TheOther.end(),
TheOther.ivec2.cbegin(),
this->begin(),
selector(target) );
}
void insert(const int& one, const int& two,const float& three ){
ivec1.push_back(one);
ivec2.push_back(two);
fvec1.push_back(three);
}
int size(){
return ivec1.size();
}
};
bool CheckIfSublistIsConnected(const Foo& list,const int& sublist_num){
Foo tmp;
tmp.const_filter( list, sublist_num );
return (bool)tmp.size();//for symplicity, othervise here is a function that check if
//the edge list represents a connected graph
}
int main(void){
Foo list;
bool connected;
list.insert(10,2,1.0);
list.insert(11,2,1.0);
list.insert(12,2,1.0);
list.insert(10,3,1.0);
list.insert(10,3,1.0);
connected=CheckIfSublistIsConnected(list,2);
if( connected ) return 0;
else return -1;
}
I've found that replacing TheOther.cbegin() / .cend() with the folowing the compiler accepts it. This means I messed up somewhere in the typedef section, but where?
thrust::make_zip_iterator(
thrust::make_tuple(
TheOther.ivec1.cbegin(),
TheOther.ivec2.cbegin(),
TheOther.fvec1.cbegin() ))

Answer 1

As it comes out I've frogotten to add the const magic word at the definition of cend/cbegin.
Dc_ListIterator cbegin() const {
return Dc_ListIterator(Dc_ListIteratorTuple( ivec1.cbegin(), ivec2.cbegin(), fvec1.cbegin() ));
}
Dc_ListIterator cend() const {
return Dc_ListIterator(Dc_ListIteratorTuple( ivec1.cend(), ivec2.cend(), fvec1.cend() ));
}