On Wed, 14 Oct 2009 10:31:06 -0400, Andrei Alexandrescu
<seewebsiteforem...@erdani.org> wrote:
Don wrote:
Well timed. I just wrote this operator overloading proposal, part 1.
http://www.prowiki.org/wiki4d/wiki.cgi?LanguageDevel/DIPs/DIP7
I concentrated on getting the use cases established.
I'm not sure multiplication is generally commutative (e.g. in linear
algebra it isn't). So why should a * x be interchangeable with x * a?
Also, the much-discussed identity:
x @= y <--> x = x @ y
is difficult to enforce statically in practice. I think some types would
want to define both to achieve good efficiency. It would be hard for the
compiler to render one unnecessary or to prove that the two are
equivalent.
Andrei
When a is a scaler, a * x <=> x * a generally holds. It's only when
something isn't a scaler, i.e. x1 * x2 != x2 * x1, that community(?)
doesn't hold.
