Re: C array to Ada pointer to unconstrained array without copying memory

["Robert I. Eachus" <rieachus@comcast.net>]

Duncan Sands wrote:

> So far so good.  Now suppose I do:
> 
> Y : Array_Pointer := new Array_Type' (X);  -- (*)
> 
> The object I want is Y.  What is the problem?  The problem
> is that line (*) involves allocating memory and copying the
> data from X to that memory.  I would like to end up with Y
> without performing the copy (and without reallocating
> memory for the array data).

What is wrong with:

Y: Array_Type;
for Y'Address use X'Address;

..if you want X and Y to be two different views of the same memory.
Notice that there is no need for an explicit pointer here, but if X is a 
  pointer as in your example, you may want to do:

Y: Array_Type;
for Y'Address use X.all'Address;

Oh, and if there is initialization for the elements of Array_Type you 
may want to add a pragma Import; to turn off initialization.
-- 
                                          Robert I. Eachus

"Quality is the Buddha. Quality is scientific reality. Quality is the 
goal of Art. It remains to work these concepts into a practical, 
down-to-earth context, and for this there is nothing more practical or 
down-to-earth than what I have been talking about all along...the repair 
of an old motorcycle."  -- from Zen and the Art of Motorcycle 
Maintenance by Robert Pirsig