Copy constructor in D. Why it is necessary to have it.

[Steven Schveighoffer]

"bearophile" wrote
> Walter Bright:
>> We've been informally calling it "deepdup". The advantage of that is it
>> is fairly hard to misinterpret. Nobody liked my ".dupofearl" idea.
>
> I agree that given the "dup", then then meaning of "deepdup" can be 
> understood much better than "clone".
>
> On the other hand there are some name changes that can improve D2:
> 1) invariant  =>  immutable

Yes

> 2) .length  =>  .size

No.  Size can imply the memory size, so an array of ints, I might expect 
size to return 4*length.

> 3) .dup  =>  .copy

either works for me.

> 4) .deepdup  =>  deepcopy

either works for me.

> 3) "dup" is used quite commonly, so it deserves a short name, but "copy" 
> is just one character longer, it isn't an abbreviation, and it's more 
> readable, so I think it's not bad.

character length is not as important as clarity, but dup seems pretty clear 
to me.  If it were copy vs. duplicate, I'd go with copy for brevity, but 
either is fine.

-Steve