Passing an array of unknown size by reference in c++ -

i have 4 sorted integer arrays, i'm trying merge 1 huge sorted array.

i merge , b gives me int array called x merge c , d gives me int array called y merge x , y z, final product.

the merge function doing same each time, storing results different array want pass in reference.

i want this:

void mergesort(int arr1[], int arr2, int &result[]){     ... }

but error "array of reference not allowed". best way this?

the syntax pass array reference in c++

int (&result)[size]

note need know size @ compile time. not want here , suggest use vector<int>.

And