# ATTRIBUTES ALLOW_NULL

The ATTRIBUTES directive option ALLOW_NULL enables a corresponding dummy argument to pass a NULL pointer (defined by a zero or the NULL intrinsic) by value for the argument.

!DIR$ ATTRIBUTES ALLOW_NULL :: arg

arg | Is the name of the argument.

ALLOW_NULL is only valid if ATTRIBUTES REFERENCE is also specified; otherwise, it has no effect.

## See Also

ATTRIBUTES
Syntax Rules for Compiler Directives