template<typename PlainObjectType, int Options_, template< class > class MakePointer_>
class Eigen::TensorMap< PlainObjectType, Options_, MakePointer_ >

A tensor expression mapping an existing array of data.

template <class> class MakePointer_ is added to convert the host pointer to the device pointer. It is added due to the fact that for our device compiler T* is not allowed. If we wanted to use the same Evaluator functions we have to convert that type to our pointer T. This is done through our MakePointer_ class. By default the Type in the MakePointer_<T> is T* . Therefore, by adding the default value, we managed to convert the type and it does not break any existing code as its default value is T*.