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From: Andreas Leitgeb <avl@logic.at>
Newsgroups: comp.lang.java.programmer
Subject: Re: How to assign an object to another in it method?
Date: Mon, 3 Jul 2017 16:28:39 -0000 (UTC)
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Jerry Stuckle <jstucklex@attglobal.net> wrote:
> On 7/3/2017 10:04 AM, Andreas Leitgeb wrote:
>> Arne Vajhøj <arne@vajhoej.dk> wrote:
>>> That is what I consider the missing default parameter issue.
>>>       // **** NOT JAVA ****
>>>       public Demo(String name, int answer = 6, boolean prisoner = false)
>> Imho this is one thing that Java actually got right, by *not* supporting.
>> In C++, default values can give a hard time when overiding methods with
>> defaults, as the default value depends on the static target object
>> type even for virtual methods.
> And how so?  It shouldn't happen if your design is correct.

Not sure what you mean...  Do you mean that one just shouldn't have
a subclass giving different defaults for the override of a virtual 
method?

Maybe.  About 20 years ago, I had a case, where I thought it made
sense, and iirc I then rewrote it to two separate methods and let
the (ditto virtual) "no-args" overload call the "arg-taking" one
with the subclass's overridden value - i.e. I ended up doing it like
one would do it in Java, anyway - and back then, I didn't yet program
Java.

I still casually use defaults in my C++ projects, but only for
non-virtual methods. And it's just syntactic sugar in those cases,
and later I usually regret it, when I need to consult the .hpp file
to see what really gets called - even within the same class.