CUDA: element of thrust::device_vector can be modified directly

 

http://code.google.com/p/thrust/wiki/QuickStartGuide#Vectors

#include <thrust/host_vector.h>
#include <thrust/device_vector.h>
#include <iostream>

int main(void)
{

// H has storage for 4 integers
thrust::host_vector<int> H(4);

// initialize individual elements
H[0] = 14;
H[1] = 20;
H[2] = 38;
H[3] = 46;

// H.size() returns the size of vector H
std::cout << "H has size " << H.size() << std::endl;

// print contents of H
for(int i = 0; i < H.size(); i++)
std::cout << "H[" << i << "] = " << H[i] << std::endl;

// resize H
H.resize(2);
std::cout << "H now has size " << H.size() << std::endl;

// Copy host_vector H to device_vector D
thrust::device_vector<int> D = H;

// elements of D can be modified
D[0] = 99;
D[1] = 88;

// print contents of D
for(int i = 0; i < D.size(); i++)
std::cout << "D[" << i << "] = " << D[i] << std::endl;

// H and D are automatically deleted when the function returns
return 0;

}