RFR 7118066: Warnings in java.util.concurrent package (original) (raw)

Rémi Forax forax at univ-mlv.fr
Tue Dec 6 08:01:51 UTC 2011

On 12/06/2011 08:07 AM, David Holmes wrote:

On 6/12/2011 12:14 PM, David Holmes wrote:

On 6/12/2011 11:45 AM, Rémi Forax wrote:

On 12/06/2011 02:12 AM, David Holmes wrote:

Is the reason for constructs like this:

HashEntry<K,V>[] tab = (HashEntry<K,V>[])new HashEntry[cap]; that we can't utilize diamond? Otherwise it would nicely reduce to: HashEntry<K,V>[] tab = new HashEntry<>[cap]; This should not compile because otherwise you can write This compiles fine: @SuppressWarnings("unchecked") public class TestGenerics<K,V> { static class HashEntry<K,V> { } public void m() { HashEntry<K,V>[] newTable = new HashEntry<>[1]; } } I don't know exactly what the type inference code does but I assumed it effectively converted the above to: HashEntry<K,V>[] newTable = (HashEntry<K,V>[]) new HashEntry[1]; and not to: HashEntry<K,V>[] newTable = new HashEntry<K,V>[1]; which of course does not compile. Hmmm. Perhaps this is a compilation accident? I don't see anything in the spec that allows diamond to be used with array creation expressions.

Yes, it's a bug of javac, eclipse compiler rejects this code.

David -----

Rémi

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