Martin Buchholz wrote:
On Thu, Sep 2, 2010 at 17:50, Joe Darcy <joe.da...@oracle.com
<mailto:joe.da...@oracle.com>> wrote:
Martin Buchholz wrote:
The usage T[] suggests that T is a reference type, as with
generics, which is not the case here.
More precisely, both the runtime types and compiletime types
of the object returned from clone of any array is identical to
its input.
Is there a non-confusing way of saying that?
How about
"...and that the return type of the {...@code clone} method of an
array type {...@code T[]} is {...@code T[]} where T is either a
reference or a primitive type."?
So I went and actually read the Object.clone spec, and it does indeed
guarantee that the (runtime) class of the returned value is the same
as the class of the argument, for arrays. As for the compile-time
type, an experiment demonstrates that the return type is indeed
exactly the same, including for non-reifiable array element types,
e.g. this compiles:
Class<? extends Number>[] a
= (Class<? extends Number>[]) (new Class<?>[42]);
Class<? extends Number>[] clone = a.clone();
So Ulf's restriction to non-reifiable T seems not to be correct.
My suggested wording is:
"...and that the return type of the {...@code clone} method of an array
type {...@code T[]} is {...@code T[]} where T is any reference or primitive
type."
Martin "Objects have class; Variables have type"
Sounds good to me; change pushed!
Thanks,
-Joe
