Return-Path: 
 <harmony-dev-return-7320-apmail-incubator-harmony-dev-archive=incubator.apache.org@incubator.apache.org>
Delivered-To: apmail-incubator-harmony-dev-archive@www.apache.org
Received: (qmail 32292 invoked from network); 11 May 2006 04:46:19 -0000
Received: from hermes.apache.org (HELO mail.apache.org) (209.237.227.199)
  by minotaur.apache.org with SMTP; 11 May 2006 04:46:19 -0000
Received: (qmail 34651 invoked by uid 500); 11 May 2006 04:38:54 -0000
Delivered-To: apmail-incubator-harmony-dev-archive@incubator.apache.org
Received: (qmail 34609 invoked by uid 500); 11 May 2006 04:38:53 -0000
Mailing-List: contact harmony-dev-help@incubator.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:harmony-dev-help@incubator.apache.org>
List-Unsubscribe: <mailto:harmony-dev-unsubscribe@incubator.apache.org>
List-Post: <mailto:harmony-dev@incubator.apache.org>
List-Id: <harmony-dev.incubator.apache.org>
Reply-To: harmony-dev@incubator.apache.org
Delivered-To: mailing list harmony-dev@incubator.apache.org
Received: (qmail 34598 invoked by uid 99); 11 May 2006 04:38:53 -0000
Received: from asf.osuosl.org (HELO asf.osuosl.org) (140.211.166.49)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 10 May 2006 21:38:53 -0700
X-ASF-Spam-Status: No, hits=0.9 required=10.0
	tests=DNS_FROM_RFC_WHOIS,SPF_PASS
X-Spam-Check-By: apache.org
Received-SPF: pass (asf.osuosl.org: domain of nbeyer@kc.rr.com designates
 24.94.166.122 as permitted sender)
Received: from [24.94.166.122] (HELO ms-smtp-02.rdc-kc.rr.com) (24.94.166.122)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 10 May 2006 21:38:53 -0700
Received: from LITTLEGUY (CPE-24-31-248-236.kc.res.rr.com [24.31.248.236])
	by ms-smtp-02.rdc-kc.rr.com (8.13.6/8.13.6) with ESMTP id k4B4cUOP002092
	for <harmony-dev@incubator.apache.org>; Wed, 10 May 2006 23:38:31 -0500 (CDT)
From: "Nathan Beyer" <nbeyer@kc.rr.com>
To: <harmony-dev@incubator.apache.org>
Subject: RE: Thanks Stepan! (was: Re: [jira] Resolved: (HARMONY-454)
 [classlib][luni] java.util.Set generics uplift and related changes)
Date: Wed, 10 May 2006 23:38:34 -0500
Message-ID: <002601c674b4$c40d0240$0e01a8c0@LITTLEGUY>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Office Outlook 11
In-reply-to: <4461D57E.4070207@gmail.com>
X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2869
Thread-index: AcZ0LsWmfHR18FPMQhqeqPQWvOCz/AAhH6VA
X-Virus-Scanned: Symantec AntiVirus Scan Engine
X-Virus-Checked: Checked by ClamAV on apache.org
X-Spam-Rating: minotaur.apache.org 1.6.2 0/1000/N

Does someone understand why this works this way? This seems so odd. I know
there are quirks to the generics syntax, but this in an edge I haven't run
into yet. I haven't been able to make this one click in my head yet.

This compiles fine:
	public synchronized void putAll(Map<? extends K,? extends V> map) {
        for (Map.Entry<? extends K,? extends V> entry : map.entrySet()) {
	      ...
        }        
	}

This won't compile at all:
	public synchronized void putAll(Map<? extends K,? extends V> map) {
        Set<Map.Entry<? extends K, ? extends V>> entries = map.entrySet();
        ...
      }
The error is: Type mismatch: cannot convert from Set<Map.Entry<capture-of ?
extends K,capture-of ? extends V>> to Set<Map.Entry<? extends K,? extends
V>>
The suggested quick fix in Eclipse is "Set<?> entries = ...".

This reports a warning:
	public synchronized void putAll(Map<? extends K,? extends V> map) {
        Map<K,V> map2 = (Map<K,V>)map;
      }
The warning is: Type safety: The cast from Map<capture-of ? extends
K,capture-of ? extends V> to Map<K,V> is actually checking against the
erased type Map
The suggested quick fix in Eclipse is to the annotation:
@SuppressWarnings("unchecked").

-Nathan


> -----Original Message-----
> From: Tim Ellison [mailto:t.p.ellison@gmail.com]
> Sent: Wednesday, May 10, 2006 6:59 AM
> To: harmony-dev@incubator.apache.org
> Subject: Thanks Stepan! (was: Re: [jira] Resolved: (HARMONY-454)
> [classlib][luni] java.util.Set generics uplift and related changes)
> 
> Stepan Mishura (JIRA) wrote:
> <snip>
> > 2) To avoid casting while-loop was replaced with for-loop. Could you
> review the change?
> 
> I was scratching my head about this cast, so I was very pleased to see
> your elegant solution.
> 
> I must admit that I don't really understand why the for-loop version is
> inherently different (other than it 'hides' the casting) -- but I've
> learned a new pattern there :-)
> 
> Regards,
> Tim
> 
> --
> 
> Tim Ellison (t.p.ellison@gmail.com)
> IBM Java technology centre, UK.
> 
> 
> ---------------------------------------------------------------------
> Terms of use : http://incubator.apache.org/harmony/mailing.html
> To unsubscribe, e-mail: harmony-dev-unsubscribe@incubator.apache.org
> For additional commands, e-mail: harmony-dev-help@incubator.apache.org


---------------------------------------------------------------------
Terms of use : http://incubator.apache.org/harmony/mailing.html
To unsubscribe, e-mail: harmony-dev-unsubscribe@incubator.apache.org
For additional commands, e-mail: harmony-dev-help@incubator.apache.org