Question

I have a fortran pointer, referring to some allocated memory. I want to “hash” it so that I get a unique number referring to that memory. In C, I would convert the pointer location to an integer.

Answer 1

In Fortran 95 I don’t believe this is possible in a strictly standard conforming way. You would need to use vendor extensions – the necessary capability is often available via an intrinsic called LOC or similar.

In Fortran 2003, depending on the nature of the object being pointed to by the Fortran pointer, you could convert the C address of the object (its memory location) to an integer.

USE, INTRINSIC :: ISO_C_BINDING, ONLY: C_LOC, C_INTPTR_T
TYPE(thing), POINTER :: object
INTEGER(C_INTPTR_T) :: an_integer
!****
ALLOCATE(object)
an_integer = TRANSFER(C_LOC(object), an_integer)