Reuse the size of assumed-shape array vs. allocate

[Beliavsky]

One difference between automatic and allocatable arrays is that the allocate statement lets you set and check a stat specifier to see if the allocation succeeded. There is no such error handling with automatic arrays. There was a thread

Difference between automatic arrays on the heap and allocatable arrays

Is there any practically significant difference between automatic arrays saved on the heap and allocatable arrays? As an example, consider the following code (edit: I added functions with array results inspired by the comment of @RonShepard). module s_mod implicit none private public :: sf_auto, sf_alloc, af_auto, af_alloc contains function sf_auto(n) result(s) integer, intent(in) :: n real :: s real :: x_auto(n) x_auto = 1.0 s = sum(x_auto) end function sf_auto function sf_alloc(n) result(…