Re: scan for int

[Richard Frith-Macdonald]

On 2005-06-27 09:24:00 +0100 Riccardo <address@hidden> wrote:

> Hello,
>
> when using an NSScanner, I can scan for an int giving a variable or a nil 
> pointer. The cocoa doc explicitly say I can do so in order to read a value 
> and skip it. In gnustep it seems to work, but I get a compiler warning. Is 
> this a gnustep problem? a gcc problem? "not a problem" :) I didn't check 
> what 
> OpenStep specs said bout this. It is not a serious problem but I just wated 
> to know.

It's certainly not a gnustep problem ... it might be a compiler problem (I 
don't know what warning the compiler generated) ... but most likely it's a 
problem in your code and/or the Macos-X documentation.

The documentation *does* say you can pass a 'nil' ... but actually that's 
misleading, since 'nil' in Objective-C is a null object (ie it has type 
'id'), but the method actually expects an argument whose type is pointer to 
integer.

Now, nil is actually a null pointer .... and a null pointer is what you must 
pass to scan the value without copying it, but the compiler may well be 
objecting about the type of the argument you are passing.

ie you should be doing

  [myScanner scanInt: (int*)0];

rather than

  [myScanner scanInt: nil];

to avoid any compiler warning.