Real view on complex array using c_pointer

[FortranFan]

@oyvind

1. Creating a “real view” into the complex array using a C pointer.

I would like to try out approach 3. Below is a module with a real_view subroutine that creates a real pointer to the complex array. Because Fortran does not allow pointers with a different type than its target I have to use a “back door” via C pointers.

Is this a good idea? Any pitfalls? Will there be a memory leakage?

With option 3, the standard conformance of the code you show requires the actual argument (c) to have the TARGET attribute as well. This is something the calling programs often forget to include with their variables. Without the TARGET, the association status of r with c is undefined upon completion of real_view subprogram.

I would be inclined instead to have the dummy argument to have the POINTER attribute and INTENT(IN) which will then require the actual argument to either have the TARGET or the POINTER attributes. This will be better on the client side and perhaps provide added flexibility there. It will then be better to include if ( associated(c) ) check in the real_view routine.