Re: Realtime cost of call by value

[pkienzle]

On 30 Oct 2003 at 13:49, John W. Eaton wrote:

> On 30-Oct-2003, address@hidden <address@hidden> wrote:
> 
> | Well, drawing a parallel from the weakly-typed nature of variables in
> | the Octave interpreter, I believe that it should be possible to have
> | these references to all types.
> 
> No, you can't have one reference that works for all types.  At least
> not a reference to the actual underlying data.  Because for that you
> need to know the exact type of the underlying data.  You can have a
> reference to a generic octave_value object, but that is not the same
> as having a reference to the actual data (which is what the OP needed
> to gain efficiency).

If I recall the example you gave many messages back,
you suggested doing a make_unique() in the code for
matrix_reference().  Since you are guaranteed nobody
else has a pointer to your data at this point, could you
not then also change its type?  

Of course this would require replacing the rep in the 
octave_value to an octave_value of the new type.  Would
a make_unique() on the octave_value solve that?

Paul Kienzle



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