◆ is_sorted() [1/4]

template<typename DerivedPolicy , typename ForwardIterator >
__host__ __device__ bool thrust::is_sorted ( const thrust::detail::execution_policy_base< DerivedPolicy > &  exec,
ForwardIterator  first,
ForwardIterator  last 

is_sorted returns true if the range [first, last) is sorted in ascending order, and false otherwise.

Specifically, this version of is_sorted returns false if for some iterator i in the range [first, last - 1) the expression *(i + 1) < *i is true.

The algorithm's execution is parallelized as determined by exec.

execThe execution policy to use for parallelization.
firstThe beginning of the sequence.
lastThe end of the sequence.
true, if the sequence is sorted; false, otherwise.
Template Parameters
DerivedPolicyThe name of the derived execution policy.
ForwardIteratoris a model of Forward Iterator, ForwardIterator's value_type is a model of LessThan Comparable, and the ordering on objects of ForwardIterator's value_type is a strict weak ordering, as defined in the LessThan Comparable requirements.

The following code demonstrates how to use is_sorted to test whether the contents of a device_vector are stored in ascending order using the thrust::device execution policy for parallelization:

#include <thrust/sort.h>
#include <thrust/sort.h>
thrust::device_vector<int> v(6);
v[0] = 1;
v[1] = 4;
v[2] = 2;
v[3] = 8;
v[4] = 5;
v[5] = 7;
bool result = thrust::is_sorted(thrust::device, v.begin(), v.end());
// result == false
thrust::sort(v.begin(), v.end());
result = thrust::is_sorted(thrust::device, v.begin(), v.end());
// result == true
See also