C++ and Java CNI: Check Java references

Jason Merrill jason_merrill@redhat.com
Wed Apr 25 11:02:00 GMT 2001

>>>>> "Tom" == Tom Tromey <tromey@redhat.com> writes:

> Last night I was thinking that maybe if we turned every pointer in CNI
> into a reference then we could have gcjh add `operator *' to every
> class automatically.  But of course this doesn't work because we would
> actually need `operator .', which C++ doesn't provide :-(.

> What if we opted to use references everywhere but kept the source
> using `->' to reference fields and such?

How would you do that?  -> only works with pointers.

> Two things with this approach that I don't yet understand:

> * Is there a performance impact for using references instead of
>   pointers as arguments to methods?  It's hard to believe there would
>   be one, but I don't know for certain.

There certainly shouldn't be.  There should be a slight performance gain
because we can assume that references are non-NULL.

I would be strongly in favor of such a change; it would make CNI code more
Java-like.  It's harder to do dangerous things with pointers if you're only
dealing with references.

> * How are objects returned from methods handled?

They can be returned by value or by reference.  Which do you mean?


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