thrust::mismatch

Defined in thrust/mismatch.h

template<typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename BinaryPredicate> thrust::pair<InputIterator1, InputIterator2> thrust::mismatch(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, BinaryPredicate pred)

mismatch finds the first position where the two ranges [first1, last1) and [first2, first2 + (last1 - first1)) differ. The two versions of mismatch use different tests for whether elements differ.

This version of mismatch finds the first iterator i in [first1, last1) such that pred(*i, *(first2 + (i - first1)) is false. The return value is a pair whose first element is i and whose second element is *(first2 + (i - first1)). If no such iterator i exists, the return value is a pair whose first element is last1 and whose second element is *(first2 + (last1 - first1)).

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

#include <thrust/mismatch.h>
#include <thrust/device_vector.h>
#include <thrust/execution_policy.h>
...
thrust::device_vector<int> vec1(4);
thrust::device_vector<int> vec2(4);

vec1[0] = 0;  vec2[0] = 0;
vec1[1] = 5;  vec2[1] = 5;
vec1[2] = 3;  vec2[2] = 8;
vec1[3] = 7;  vec2[3] = 7;

using Iterator = thrust::device_vector<int>::iterator;
thrust::pair<Iterator,Iterator> result;

result = thrust::mismatch(thrust::device, vec1.begin(), vec1.end(), vec2.begin(), thrust::equal_to<int>());

// result.first  is vec1.begin() + 2
// result.second is vec2.begin() + 2