template struct cvflann::Hamming

Hamming distance functor (pop count between two binary vectors, i.e. xor them and count the number of bits set) That code was taken from brief.cpp in OpenCV

#include <dist.h>

template <class T>
struct Hamming
{
    // typedefs

    typedef T ElementType;
    typedef False is_kdtree_distance;
    typedef False is_vector_space_distance;
    typedef int ResultType;

    // methods

    template <
        typename Iterator1,
        typename Iterator2
        >
    ResultType
    operator()(
        Iterator1 a,
        Iterator2 b,
        size_t size,
        ResultType = -1
        ) const;
};