[bind10-dev] Operators

[JINMEI Tatuya / 神明達哉]

At Tue, 21 Feb 2012 11:46:11 +0100,
Michal 'vorner' Vaner <michal.vaner at nic.cz> wrote:

> > On a related note; should we also by default overload the relevant
> > operators if we have their corresponding methods? (i am just writing
> > one that has an equals() for instance)

In the original context, one question is whether to support
operator<<(ostream&, OurClass&) for our classes.  And, in general I
think it's a good practice as long as we can define a reasonable
textual representation of the class objects (so, for example, I'd say
if a class has a toText() method we should also define operator<< for
it).

The other is whether to support operator==.  For this, and for other
operators, my opinion is that it's case by case basis.  On one hand, I
like the brevity and possibly much more intuitive representation as a
result of operator overloading.  On the other hand, its brevity can
often make the intent unclear and lead to confusion and surprising
results.  So, it would be a good check point in review when someone
wants to introduce a new overloaded operator - if it's not super clear
for the reviewer, it's probably not as good as it might look for the
original developer.

On a further related note: we have this in our coding guideline:
http://bind10.isc.org/wiki/CodingGuidelines#OperatorOverloading
"When a class supports operator overloading, then there should also be
non-overloaded methods".  I don't know the rationale of this guide,
and, as a matter of fact, we don't follow this rule so consistently.
If it really makes sense, we should make sure we do it more
consistently; if the rationale isn't clear and we actually don't
follow it anyway, I think we should rather remove it from the guide.

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.