gcc.info: Pointer Arith

Go forward to Initializers
Go backward to Subscripting
Go up to C Extensions
Go to the top op gcc

Arithmetic on `void'- and Function-Pointers

   In GNU C, addition and subtraction operations are supported on
pointers to `void' and on pointers to functions.  This is done by
treating the size of a `void' or of a function as 1.
   A consequence of this is that `sizeof' is also allowed on `void' and
on function types, and returns 1.
   The option `-Wpointer-arith' requests a warning if these extensions
are used.