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Groups > comp.lang.java.programmer > #26226

Re: limitations on using enum as generic parameter

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On Feb 8, 1:34 pm, markspace <nos...@nowhere.com> wrote:
> On 2/8/2011 9:50 AM, dal...@cs.queensu.ca wrote:
>
> > situations, I tried writing a generic class that takes an enum as a
> > type parameter.  Unfortunately I don't seem to be able to invoke the
> > enum's values() method -- javac says "Cannot find symbol: method
>
> Yes, values() and valueOf(String) are /static/ methods.  They don't
> appear on the Enum interface so the compiler doesn't know about them.
>
> You can try object.getClass().getEnumConstants() to get the constants
> themselves in order.
>
> Also you should probably be declaring you enum as <E extends Enum<E> & ...>.
>
> Untested:
>
> public class EnumCodeSet<E extends Enum<E> & MessageCode>
> {
>    private final E[] enums;
>
>    public EnumCodeSet( E anEnum ) {
>      enums = anEnum.getClass().getEnumConstants);
>    }
>
>    public MessageCode index( int i ) {
>      return enums[i];
>    }
>
>    //... etc.
>
>
>
>

Also, generics and arrays don't mix.  So don't mix them.

--
Lew

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limitations on using enum as generic parameter "dalamb@cs.queensu.ca" <david.alex.lamb@gmail.com> - 2011-02-08 09:50 -0800
  Re: limitations on using enum as generic parameter Lew <noone@lewscanon.com> - 2011-02-11 07:36 -0500
  Re: limitations on using enum as generic parameter Daniele Futtorovic <da.futt.news@laposte.net.invalid> - 2011-02-08 20:36 +0100
  Re: limitations on using enum as generic parameter Ken Wesson <kwesson@gmail.com> - 2011-02-08 19:46 +0100
  Re: limitations on using enum as generic parameter Roedy Green <see_website@mindprod.com.invalid> - 2011-02-10 22:50 -0800
  Re: limitations on using enum as generic parameter Roedy Green <see_website@mindprod.com.invalid> - 2011-02-10 22:47 -0800
  Re: limitations on using enum as generic parameter markspace <nospam@nowhere.com> - 2011-02-08 10:34 -0800
    Re: limitations on using enum as generic parameter Lew <lew@lewscanon.com> - 2011-02-08 10:38 -0800

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