thrust::merge

Defined in thrust/merge.h

template<typename DerivedPolicy, typename InputIterator1, typename InputIterator2, typename OutputIterator, typename StrictWeakCompare> OutputIterator thrust::merge(const thrust::detail::execution_policy_base<DerivedPolicy> &exec, InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, OutputIterator result, StrictWeakCompare comp)

merge combines two sorted ranges [first1, last1) and [first2, last2) into a single sorted range. That is, it copies from [first1, last1) and [first2, last2) into [result, result + (last1 - first1) + (last2 - first2)) such that the resulting range is in ascending order. merge is stable, meaning both that the relative order of elements within each input range is preserved, and that for equivalent elements in both input ranges the element from the first range precedes the element from the second. The return value is result + (last1 - first1) + (last2 - first2).

This version of merge compares elements using a function object comp.

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

The following code snippet demonstrates how to use merge to compute the merger of two sets of integers sorted in descending order using the thrust::host execution policy for parallelization:

#include <thrust/merge.h>
#include <thrust/functional.h>
#include <thrust/execution_policy.h>
...
int A1[6] = {11, 9, 7, 5, 3, 1};
int A2[7] = {13, 8, 5, 3, 2, 1, 1};

int result[13];

int *result_end = thrust::merge(thrust::host,
                                A1, A1 + 6,
                                A2, A2 + 7,
                                result,
                                thrust::greater<int>());
// result = {13, 11, 9, 8, 7, 5, 5, 3, 3, 2, 1, 1, 1}