Don wrote:
There's been some interesting discussion about operator overloading over
the past six months, but to take the next step, I think we need to
ground it in reality. What are the use cases?
I think that D's existing opCmp() takes care of the plethora of trivial
cases where <, >= etc are overloaded. It's the cases where the
arithmetic and logical operations are overloaded that are particularly
interesting to me.
The following mathematical cases immediately spring to mind:
* complex numbers
* quaternions (interesting since * is anti-commutative, a*b = -b*a)
* vectors
* matrices
* tensors
* bigint operations (including bigint, bigfloat,...)
I think that all of those are easily defensible.
But I know of very few reasonable non-mathematical uses.
In C++, I've seen them used for iostreams, regexps, and some stuff that
is quite frankly bizarre.
So, please post any use cases which you consider convincing.
I've seen | and & used for fluent interfaces in C#:
Assert.That(0, Is.GreaterThan(-1) & Is.LessThan(1));
That is a bit awkward, a bit forced. In this situation, you want to use
&& or ||, which is possible by defining an implicit cast to bool in C#,
but D wouldn't use that cast (I think, hopefully I'm wrong). This would
mess up autocomple-- er, wait, that term isn't backed by Microsoft's
army of lawyers. It would mess up Microsoft(r) Intellisense(tm).
