Do I need to free device_ptr returned by thrust?

Question

I have a function to get the minimum value of an array and it's executed within a loop.

thrust::device_ptr<float> min_ptr = thrust::min_element(populationFitness, populationFitness + POPULATION);

Do I have to free the returned device_ptr? I tried with thrust::device_free(min_ptr) but an exception is thrown.

Answer 1

thrust::min_element returns an iterator. You should not free it directly.

Answer 2

I dont think you need to free the memory returned by the thrust::min_element

Looking at the example code given at http://docs.thrust.googlecode.com/hg/group__extrema.html

#include <thrust/extrema.h>
...
int data[6] = {1, 0, 2, 2, 1, 3};
int *result = thrust::max_element(data, data + 6);

Seems that it returns an pointer to the array element and you need not delete it .