Intel® Fortran Compiler 17.0 Developer Guide and Reference
An assumed-size array is a dummy argument array that assumes the size (only) of its associated actual argument array; the rank and extents can differ for the actual and dummy arrays. An assumed-size specification takes the following form:
([expli-shape-spec,] [expli-shape-spec,] ... [dl:] *)
expli-shape-spec |
Is an explicit-shape specification. |
dl |
Is a specification expression indicating the lower bound of the dimension. The expression can have a positive, negative, or zero value. If necessary, the value is converted to integer type. If the lower bound is not specified, it is assumed to be 1. |
* |
Is the upper bound of the last dimension. |
The rank of the array is the number of explicit-shape specifications plus 1.
The size of the array is assumed from the actual argument associated with the assumed-size dummy array as follows:
If the actual argument is an array of type other than default character, the size of the dummy array is the size of the actual array.
If the actual argument is an array element of type other than default character, the size of the dummy array is a + 1 - s, where s is the subscript order value and a is the size of the actual array.
If the actual argument is a default character array, array element, or array element substring, and it begins at character storage unit b of an array with n character storage units, the size of the dummy array is as follows:
MAX(INT((n + 1 - b)/y), 0)The y is the length of an element of the dummy array.
An assumed-size array can only be used as a whole array reference in the following cases:
When it is an actual argument in a procedure reference that does not require the shape
In the intrinsic function LBOUND
Because the actual size of an assumed-size array is unknown, an assumed-size array cannot be used as any of the following in an I/O statement:
An array name in the I/O list
A unit identifier for an internal file
A run-time format specifier
The following is an example of an assumed-size specification:
SUBROUTINE SUB(A, N)
REAL A, N
DIMENSION A(1:N, *)
...The following example shows that you can specify lower bounds for any of the dimensions of an assumed-size array, including the last:
SUBROUTINE ASSUME(A)
REAL A(-4:-2, 4:6, 3:*)