Path: csiph.com!news.mixmin.net!aioe.org!.POSTED!not-for-mail
From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= <arne@vajhoej.dk>
Newsgroups: comp.lang.java.programmer
Subject: Re: Java 8 Lambda with generic types
Date: Sun, 28 Aug 2016 13:22:43 -0400
Organization: Aioe.org NNTP Server
Lines: 37
Message-ID: <npv6l1$9c8$1@gioia.aioe.org>
References: <df44fc1a-9d48-4ba8-890e-a687d24062a9@googlegroups.com> <9ff6ad3e-bb82-4207-91d8-f03c707a1dcf@googlegroups.com>
NNTP-Posting-Host: 7SK6yTFfqwlIPNBLl3l7Qg.user.gioia.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Complaints-To: abuse@aioe.org
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0
X-Notice: Filtered by postfilter v. 0.8.2
Xref: csiph.com comp.lang.java.programmer:35490

On 8/28/2016 10:45 AM, Stone Zhong wrote:
> Having checkToy take generic parameter is a workaround, but it does not solve the problem which it does not work with <?>. For example, if you have:
>
>
>     public static void checkToys(Toy<?> ... toys) {
>     }
>
> You cannot put a generic type here for checkToys, and you cannot call
>
>         checkToys(
>             () -> Arrays.<Integer>asList(10),
>             () -> Arrays.<String>asList("hello")
>         );
>
> But you can do
>
>         checkToys(
>             new Toy<Integer>() {
>                 @Override
>                 public List<Integer> get() {
>                     return Arrays.<Integer>asList(1, 2, 3);
>                 }
>             },
>             new Toy<String>() {
>                 @Override
>                 public List<String> get() {
>                     return Arrays.<String>asList("a", "b", "c");
>                 }
>             }
>         );

@SuppressWarnings("rawtypes")
public static void checkToys(Toy ... toys) {

Arne