◆ copy_n() [2/2]

template<typename InputIterator , typename Size , typename OutputIterator >
OutputIterator thrust::copy_n ( InputIterator  first,
Size  n,
OutputIterator  result 

copy_n copies elements from the range [first, first + n) to the range [result, result + n). That is, it performs the assignments *result = *first, *(result + 1) = *(first + 1), and so on. Generally, for every integer i from 0 to n, copy performs the assignment *(result + i) = *(first + i). Unlike std::copy_n, copy_n offers no guarantee on order of operation. As a result, calling copy_n with overlapping source and destination ranges has undefined behavior.

The return value is result + n.

firstThe beginning of the range to copy.
nThe number of elements to copy.
resultThe beginning destination range.
The end of the destination range.
Template Parameters
InputIteratormust be a model of Input Iterator and InputIterator's value_type must be convertible to OutputIterator's value_type.
Sizeis an integral type.
OutputIteratormust be a model of Output Iterator.
result may be equal to first, but result shall not be in the range [first, first + n) otherwise.

The following code snippet demonstrates how to use copy to copy from one range to another.

#include <thrust/copy.h>
size_t n = 100;
thrust::copy_n(vec0.begin(), n, vec1.begin());
// vec1 is now a copy of vec0
See also