> -----Original Message-----
> From: piclist-bounces@MIT.EDU On Behalf Of John Temples
> Sent: Thursday, July 22, 2010 12:37 PM
> 
> On Thu, 22 Jul 2010, Paul Hutchinson wrote:
> 
> > The parameter identifiers in a C function prototype are optional
> 
> No, they aren't.  A function declaration that doesn't specify the
> number and types of the parameters is not a function prototype.
> Something like this:
> 
> void func();
> 
> void main(void)
> {
>      func();
> }
> 
> will correctly generate a "missing prototype" warning from some
> compilers (e.g., Microchip's C18).

Only identifiers are optional, the types are not optional. Your example
leaves out both making it an invalid function prototype.

Here's an example of a valid prototype in ANSI C without an identifier.

void func(int); 

It gives the type and number of parameters but does not include an
identifier.

The C99 standard (Section 6.7.5.3 paragraph 6) says: 
"A parameter type list specifies the types of, and may declare identifiers
for, the
parameters of the function."

Paul Hutch

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