RFR(s): 8060192: Add default method Collection.toArray(generator) (original) (raw)

Paul Sandoz paul.sandoz at oracle.com
Tue Dec 5 19:35:37 UTC 2017


On 5 Dec 2017, at 11:19, Stuart Marks <stuart.marks at oracle.com> wrote:

On 12/5/17 10:47 AM, Paul Sandoz wrote: 345 *

Suppose {@code x} is a collection known to contain only strings.

346 * The following code can be used to dump the collection into a newly 347 * allocated array of {@code String}: Make it an API note? (same for toArray(T[]) Will do. 352 * @implSpec 353 * The default implementation calls the generator function with zero 354 * and then passes the resulting array to {@link #toArray(T[])}. That’s reasonable. I pondered about being vague and specifying a value in the range if [0, size()), to allow wiggle room for using 0 or size(). No, I really think it has to be exactly zero. If the default were to choose some value K < size(), the collection size could change to be smaller than K after allocation but before the call to toArray(T[]), resulting in an array that is unexpectedly large.

Ah yes, concurrent collections.

Paul.

360 * @throws ArrayStoreException if the runtime type of any element in this 361 * collection is not assignable to the {@linkplain Class#getComponentType 362 * runtime component type} of array returned by the generator function s/of array returned by the generator function/of the generated array/ ? Will do. s'marks



More information about the core-libs-dev mailing list