Swap two arrays (using pointers, not copy)
Figured it out. Though using new works, I wanted to keep the buffers out of the heap. The following declarations work with the swap code:

uint8_t a1[10];
uint8_t a2[10];
uint8_t *array1 = a1;
uint8_t *array2 = a2;

uint8_t *tmp = array1;
array1 = array2;
array2 = tmp;