Method operator-

benchmarks/tbb/concurrent_vector.h:355–357

            return *this;
        }
        vector_iterator operator-( ptrdiff_t offset ) const {
            return vector_iterator( *my_vector, my_index-offset );
        }
        vector_iterator &operator-=( ptrdiff_t offset ) {
            my_index-=offset;
            my_item = NULL;