[J3] [EXTERNAL] Re: Why is += missing?

[Malcolm Cohen]

> Maybe I’ve not properly understood your point though, as I don’t see how it _undermines_ existing modules. Those + and = implementations remain valid.    They just would not automatically confer the new “+=”.

 

That is precisely my point.

 

A future user using

   X += Y

thinking this will do X = X + Y, as it does for many intrinsic types and newly-written modules, will not get that. With reasonable luck they’ll get an inscrutable error message at compile time, with bad luck they’ll stumble across a compiler extension (like Integer=Logical or the like) and get silent wrong results.

 

Mostly I’d expect they’d get an error, so it’s not like it would be *destroying* existing modules, but it certainly undermines them.

 

Cheers,

-- 

..............Malcolm Cohen, NAG Oxford/Tokyo.

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