ASSOCIATED

result = ASSOCIATED (pointer [, target])

pointer	(Input) Must be a pointer. It can be of any data type. The pointer association status must be defined.
target	(Input; optional) Must be a pointer or target. If it is a pointer, the pointer association status must be defined.

Results

The result is a scalar of type default logical. The setting of compiler options specifying integer size can affect this function.

If only pointer appears, the result is true if it is currently associated with a target; otherwise, the result is false.

If target also appears and is a target, the result is true if pointer is currently associated with target; otherwise, the result is false.

If target is a pointer, the result is true if both pointer and target are currently associated with the same target; otherwise, the result is false. (If either pointer or target is disassociated, the result is false.)

Example

REAL C (:), D(:), E(5)
POINTER C, D
TARGET E
LOGICAL STATUS
C => E                       ! pointer assignment
D => E                       ! pointer assignment
STATUS = ASSOCIATED(C)       ! returns TRUE; C is associated
STATUS = ASSOCIATED(C, E)    ! returns TRUE; C is associated with E
STATUS = ASSOCIATED (C, D)   ! returns TRUE; C and D are associated
                             !   with the same target

Consider the following:

   REAL, TARGET, DIMENSION (0:50) :: TAR
   REAL, POINTER, DIMENSION (:) :: PTR
   PTR => TAR
   PRINT *, ASSOCIATED (PTR, TAR)      ! Returns the value true

The subscript range for PTR is 0:50. Consider the following pointer assignment statements:

   (1) PTR => TAR (:)
   (2) PTR => TAR (0:50)
   (3) PTR => TAR (0:49)

For statements 1 and 2, ASSOCIATED (PTR, TAR) is true because TAR has not changed (the subscript range for PTR in both cases is 1:51, following the rules for deferred-shape arrays). For statement 3, ASSOCIATED (PTR, TAR) is false because the upper bound of TAR has changed.

Consider the following:

   REAL, POINTER, DIMENSION (:) :: PTR2, PTR3
   ALLOCATE (PTR2 (0:15))
   PTR3 => PTR2
   PRINT *, ASSOCIATED (PTR2, PTR3)       ! Returns the value true
   ...
   NULLIFY (PTR2)
   NULLIFY (PTR3)
   PRINT *, ASSOCIATED (PTR2, PTR3)       ! Returns the value false