Pointers and Targets

Unlike C pointers, F90 pointers are much less flexible and more highly optimized. The space to which a F90 pointer ``points'' is called a target.

Several restrictions

• F90 pointers are strongly typed: e.g. a pointer to a REAL, scalar target may not point to any other data type; similarly, a pointer to a REAL 1D array cannot point to a REAL 2D array;
• any variable that is pointed at must have the TARGET attribute;
• pointers are automatically dereferenced (the pointer name and the target name reffer to the same memory location);
• it is not possible to print out the address of the target of a pointer.

Benefits: provide a more flexible alternative to allocatable arrays, and allow the creation and manipulation of linked lists, etc.