HP C Programmer's Guide (92434-90009)

Chapter 5 139
Programming for Portability
Porting to ANSI Mode HP C
struct s x;
{
/* Function body using the old method for
declaring function parameter types
*/
}
int new_way(struct s x)
{
/* Function body using the new method for
declaring function parameter types
*/
}
/* The functions "old_way" and "new_way" are
both called later on in the program.
*/
old_way(1); /* This call compiles without complaint. */
new_way(1); /* This call gives an error. */
In this example, the function new_way gives an error because the value being passed to
it is of type int instead of type struct
x.
• More efficient parameter passing in some cases. Parameters of type float are not
converted to double. For example:
void old_way(f)
float f;
{
/* Function body using the old method for
declaring function parameter types
*/
}
void new_way(float f)
{
/* Function body using the new method for
declaring function parameter types
*/
}
/* The functions "old_way" and "new_way" are
both called later on in the program.
*/
float g;
old_way(g);
new_way(g);
In the above example, when the function old_way is called, the value of g is converted
to a double before being passed. In ANSI mode, the old_way function then converts the
value back to float. When the function new_way is called, the float value of g is passed
without conversion.
• Automatic conversion of function arguments, as if by assignment. For example, integer
parameters may be automatically converted to floating point.
/* Function declaration using the new method