Dereference iterator via get_value(derived_cast(exec),iterator)
Dereference iterator via get_value(derived_cast(exec),iterator)

This allows peeking into the device data when exec is device policy
and the iterator is a raw device pointer, thus fixing
{min,max,minmax}_element in such setup.

jaredhoberock/thrust,egaburov/thrust,andrewcorrigan/thrust-multi-permutation-iterator,andrewcorrigan/thrust-multi-permutation-iterator,thrust/thrust,jaredhoberock/thrust,thrust/thrust,thrust/thrust,sdalton1/thrust,thrust/thrust,jaredhoberock/thrust,egaburov/thrust,egaburov/thrust,sdalton1/thrust,andrewcorrigan/thrust-multi-permutation-iterator,jaredhoberock/thrust,sdalton1/thrust,jaredhoberock/thrust,thrust/thrust