thrust::is_sorted

Defined in thrust/sort.h

template<typename DerivedPolicy, typename ForwardIterator, typename Compare> bool thrust::is_sorted(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, ForwardIterator first, ForwardIterator last, Compare comp)

is_sorted returns true if the range [first, last) is sorted in ascending order according to a user-defined comparison operation, and false otherwise.

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

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

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

#include <thrust/sort.h>
#include <thrust/functional.h>
#include <thrust/device_vector.h>
#include <thrust/execution_policy.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;

thrust::greater<int> comp;
bool result = thrust::is_sorted(thrust::device, v.begin(), v.end(), comp);

// result == false

thrust::sort(v.begin(), v.end(), comp);
result = thrust::is_sorted(thrust::device, v.begin(), v.end(), comp);

// result == true

See also

sort

See also

stable_sort

See also

less<T>

Parameters

exec – The execution policy to use for parallelization.
first – The beginning of the sequence.
last – The end of the sequence.
comp – Comparison operator.

Template Parameters

DerivedPolicy – The name of the derived execution policy.
ForwardIterator – is a model of Forward Iterator, and ForwardIterator's value_type is convertible to both StrictWeakOrdering's first_argument_type and second_argument_type.
Compare – is a model of Strict Weak Ordering.

Returns

true, if the sequence is sorted according to comp; false, otherwise.