Re: Cast to derived class?

"Alf P. Steinbach" <>
Mon, 12 Nov 2007 19:30:28 +0100
* Juha Nieminen:

Alf P. Steinbach wrote:

    int getA() {
        return a_;

The prefix "get" serves no useful purpose. It just clutters the code
and incorrectly indicates some dynamic action to obtain the value.

  What kind of strange principle is that?

  So what if it "incorrectly indicates some dynamic action"? It's a
public interface. You *don't know* what it does inside. You *don't care*
what it does inside. It could perform an SQL database search for all you
know. The only thing you care is what it's defined to do, ie. it returns
a specified value, and that's it.

  "get<something>()" is a perfectly valid and good member function name.
It's descriptive and concise, and above all, it's abstract. It hides the
actual implementation, which is good.

  If it was somehow named after what it actually does (eg. simply
returns a member variable), then what happens if in the future its
implementation is changed to something else? Are you going to change the
name of the function to reflect that?

getSomething is technically valid but not good: it's ungood.

It is a Java'ism. In Java it serves a technical purpose for the kind of
name you applied it to. In C++ it does not.





"Get" it?

Probably not -- you'll get it long after this, and then wonder about
what you could have been thinking earlier -- but anyway, also consider

   void getLargeDataSet( std::vector<double>& v ) { ... }

   // Wrapper for ease of use, relying on RVO.
   std::vector<double> largeDataSet()
       std::vector<double> result;
       getLargeDataSet( result );
       return result;

where the two name forms play different roles. If you use "get"
indiscriminately for a completely (worse than) useless purpose, as you
did, you lose the ability to use "get" for something useful, as above.

Cheers, & hth.,

- Alf

A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

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