11.1.5 Argument-Passing by Reference or Value

In general, Fortran routines pass arguments by reference. In a call, if you enclose an argument with the nonstandard function %VAL(), the calling routine passes it by value.

The standard Fortran 95 way to pass arguments by value is the VALUE attribute and through INTERFACE blocks. See 11.4 Passing Data Arguments by Value.

In general, C passes arguments by value. If you precede an argument by the ampersand operator (&), C passes the argument by reference using a pointer. C always passes arrays and character strings by reference.