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Re: Today I invented ... the downcast!

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On 12/24/2015 2:39 PM, Stefan Ram wrote:
>    What do you all thing about it?

     Meh.

>    Example of the intended usage:
>
> final android.widget.LinearLayout.LayoutParams parameters
> = downcast( params );
>
>    Definition:
>
> static private final< T, O >T downcast( O x ){ return( T )x; }
>
>    Main Advantage (that's why I wrote it):
>
>        - the programmer conveys his intention that this
>          cast is intended to be a /down/cast

     Since an /up/cast requires no cast operator at all, the mere
presence of the cast is a pretty good indicator.  Besides,

	String s = "I feel sad and downcast. (:";
	Object o = downcast(s);  // "down?"

>    Advantages that are mere side-effects of the implementation:
>
>        - the programmer does not actually have to write
>          the target type, which is deduced
>
>    Disadvantage:
>
>        - It has not yet been extensively tested
>
>        - It does not check at compile time whether T
>          really is a /sub/type of O.

    ... thus converting a compile-time error into a run-time error,
a wrong in the step direction.  Hmm: I withdraw my "Meh" above, and
change it instead to "Ugh."

-- 
esosman@comcast-dot-net.invalid
"Don't be afraid of work. Make work afraid of you." -- TLM

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Re: Today I invented ... the downcast! Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-12-24 15:12 -0500
  Re: Today I invented ... the downcast! Lew <lewbloch@gmail.com> - 2015-12-24 13:11 -0800

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