Hi,
I would like to raise a couple of points about the iterator adaptors.
Firstly, is it really necessary to have the predicate as part of the
template specification for the filter_iterator? Surely it can be assumed
that it will always be convertible to boost::function ?
Secondly, by allowing the return type of the function used by the
transform_iterator to be a reference can we not use it to implement a more
generic form of indirect_iterator? The code below gives a flavour of the idea.
struct dereference
{
typedef int result_type;
int* data_;
dereference(int* data):data_(data){}
int operator()(int i) const { return data_[i]; }
};
int main()
{
int data[] = { 1,2,3,4,5,6,7,8 };
int keys[] = { 0,3,1,6,5,4,2,7 };
typedef boost::transform_iterator_generator::type
indirect_iterator;
indirect_iterator i(keys, dereference(data)),
i_end(keys+8,dereference(data));
while(i != i_end)
std::cout << *i++ << ' ';
return 0;
}
The output is:
1 4 2 7 6 5 3 8
Witz
