null(3I)

NAME
     NULL - Returns a disassociated pointer

SYNOPSIS
     NULL ([[MOLD=]mold])

STANDARDS
     Fortran

DESCRIPTION
     The NULL intrinsic function returns a disassociated pointer.  It
     accepts the following argument:

     mold      A pointer of any type.  This is an optional argument.  Its
               pointer association status can be undefined, disassociated,
               or associated.  If its status is associated, the target need
               not be defined with a value.

               mold must be specified when a reference to NULL appears as
               an actual argument in a reference to a generic procedure if
               the type, type parameters, or rank is required to resolve
               the generic reference.

     This is a transformational function.

RETURN VALUES
     NULL returns a disassociated pointer.  The pointer has no shape, but
     it does have rank.

     If mold is specified, the return value has the same characteristics as
     mold.

     If mold is not specified, the data type, type parameters, and rank of
     the result are determined by the pointer that becomes associated with
     the result, as follows:

     Appearance of NULL:                               Result type, type
                                                       parameters, rank:

     Right side of a pointer assignment                Pointer on the left
                                                       side

     Initialization for an object in a declaration     The object

     Default initialization for a component            The component

     In a structure constructor                        The corresponding
                                                       component

     As an actual argument                             The corresponding
                                                       dummy argument

     In a DATA statement                               The corresponding
                                                       pointer object

EXAMPLES
          INTERFACE GEN
             SUBROUTINE S1 (J, PI)
                INTEGER J
                INTEGER, POINTER :: PI
             END SUBROUTINE S1
             SUBROUTINE S2 (K, PR)
                INTEGER K
                REAL, POINTER :: PR
             END SUBROUTINE S2
          END INTERFACE
          REAL, POINTER :: REAL_PTR
          CALL GEN (7, NULL (REAL_PTR) )    ! INVOKE S2