Difference between automatic arrays on the heap and allocatable arrays

[zaikunzhang]

@RonShepard

But a function result must be a little different somehow. In this case, the automatic or allocatable entity must live a little longer since it is used in an expression in the calling program. How exactly does that work, is it different for automatic and allocatable function return results, and is there any practical (e.g. performance) difference?

Thank you for the comments. You are right. This case is even more interesting than the senario where the arrays are only local variables. I have edited my post to include such functions.