Operator overloading

[John Reimer]

Hello Andrei,

> The Anh Tran wrote:
> 
>> Andrei Alexandrescu wrote:
>> 
>>>> auto op(++)(); // bar++
>>>> auto op(++)(int); // ++bar
>>> Hey, wasn't the implementation of the postincrement operator through
>>> an overload a rather untasty hack?
>>> 
>>> Aside for a minor change in notation, there's no improvement. We're
>>> looking for much more broad improvements, such as offering the
>>> ability to overload several operators with only one function.
>>> 
>>> Andrei
>>> 
>> How about this:
>> 
>> Unary op: ++f, ~f, ~f, +f, -f, *f
>> auto operator(++, --, ~, !, +, -, *)()
>> {
>> // posfix is provided by compiler
>> // and is only used for: foo++ foo--
>> static if (posfix)
>> return op(this.value);
>> else ...
>> }
>> Binary op: equality comparison f1 <= f2
>> bool operator(<, >, <=, >=, ==, !=)(Foo foo)
>> {
>> return op(this.value, foo.value);
>> }
>> For un-order object, he/she just list 'correct' operator(s) in op()
>> list. Ex: bool operator(!=, ==)(Foo foo) {}
>> 
> Why invent new syntax when compile-time strings are already there?
> 
> auto operator(string op)() if (op == "++" || op == "--")
> {
> return mixin(op ~ "this.value");
> }
> etc. That, of course, is orthogonal to the semantic equivalences
> suggested by Don and does not solve fusion.
> 
> Andrei
> 


Once again, I'm no expert in this matter, but the compiler-time strings idea 
looks like a great solution for this.  Was this brought up before? ...because 
that was kind of what I was thinking when you mentioned a new operator overloading 
syntax for D.

-JJR