How to return an array that is the result of an overload?

Question

C++ / C#

There is a task: to
overload the bitwise shift to the left so that it creates one one-dimensional array sorted in ascending order from two one-dimensional arrays. The question is actually about overloading - you need to transfer two arrays, two values ​​\u200b\u200bof the length of these arrays, and get one array at the output.
And as I understand it, the result in main should be something like this
T = A[N] << B[M];