Why Java Doesn't Need Operator Overloading (and Very Few Languages Do, Really)

[Christopher Wright]

Don wrote:
> Paul D. Anderson wrote:
>> Sounds like someone needs a strong dose of D!!
>>
>> http://java.dzone.com/articles/why-java-doesnt-need-operator
>>
>> The comments bounce between "operator overloading is always bad 
>> because you can do idiotic things with it" and "operator overloading 
>> is essential because sometimes you really need it".
>>
>> How about a language where operator overloading is available for the 
>> cases where you do really need it, but isn't available in general?
>>
>> Hmmm...
>>
>> Paul
> He says he doesn't like it because:
> 
> The number of operators that you can overload is very small and each of 
> them is attached to very specific semantics that makes little sense 
> outside the realm of scalars and of a few other specialized mathematical 
> concepts (e.g. matrices).
> 
> Bingo! That's what operator overloading is for. **Don't overload 
> arithmetic operators unless you are doing arithmetic.** I think the main 
> problem with operator overloading in C++ is that that point wasn't 
> explained well at all. The D spec could probably do a better job of it, 
> but at least the ~ operator removes the temptation for people to use + 
> to mean concatenation.

This reminds me of something I did at work. C# 2.0 has no builtin syntax 
for associative arrays, and we needed to create a lot of dictionaries of 
string -> object. We came up a little class with operator overloads: 
operator[string,object] added a dictionary entry and returned the 
dictionary builder. But when you're done with that, you still need to 
convert to a dictionary. So we added an operator overload for this.

Now we format strings like:
_formatter.Format("${hello} ${world}", -Using.Values["hello", 
helloObject]["world", worldObject]);