HP Fortran Programmer's Reference (September 2007)

Arrays

Array declarations

Chapter 3 63

Deferred-shape arrays

A deferred-shape array has either the POINTER attribute or the ALLOCATABLE attribute. Its

shape is not speciﬁed until the array is pointer assigned or allocated. Although a

deferred-shape array can have the same form as an assumed-shape array, the two are

different. The assumed-shape array is a dummy argument and must not have the POINTER

attribute.

The array speciﬁcation for a deferred-shape array has the form:

: [ , : ] ...

The speciﬁcation for a deferred-shape array deﬁnes its rank but not the bounds. The bounds

are deﬁned either when the array is allocated or when an array pointer becomes associated

with a target.

Array pointers and allocatable arrays are described in the following sections.

Array pointers

An array pointer is a deferred-shape array with the POINTER attribute. Its bounds and

shape are deﬁned only when the array is associated with a target in a pointer assignment

statement or in an ALLOCATE statement. An array pointer must not be referenced until it is

associated.

Following are example declarations of array pointers:

! p1 is declared as a pointer to a rank-one

! array of type real; p1 is not associated with any target

REAL, POINTER, DIMENSION(:) :: p1

! p2 is a pointer to an integer array of rank-two;

! it must be associated with a target before it can be referenced

INTEGER, POINTER :: p2(:,:)

! err is a pointer to a rank-3 array of type err_type

TYPE err_type

INTEGER :: class

REAL :: code

END TYPE err_type

TYPE(err_type), POINTER, DIMENSION(:,:,:) :: err

! The next statement is ILLEGAL: pointers cannot have an

! explicit shape.

INTEGER, POINTER :: p3(n)

For information about associating an array pointer with a target, see “Pointers” on page 131.

For information about the POINTER attribute and ALLOCATE statement, see Chapter 10, “HP

Fortran Statements.”