Return array in a function

Question

I have an array int arr[5] that is passed to a function fillarr(int arr[]):

int fillarr(int arr[])
{
    for(...);
    return arr;
         


        

Answer 1

template
using ARR_REF = T (&)[N];

template 
ARR_REF ArraySizeHelper(ARR_REF arr);

#define arraysize(arr) sizeof(ArraySizeHelper(arr))