On Sunday, 18 August 2013 at 21:23:05 UTC, Namespace wrote:
On Sunday, 18 August 2013 at 15:29:26 UTC, Ali Çehreli wrote:
On 08/18/2013 07:34 AM, Namespace wrote:
> In C++ you can declare operator overloads inside and outside
of classes
> (the latter is more popular)
The latter is popular because a global operator takes
advantage of implicit type conversions. A global operator+
allows using an int even on the left-hand side of the operator.
As a result, assuming that MyInt can be constructed from an
int, when there is
// Assume this is defined outside of MyInt definition
MyInt operator+(MyInt lhs, MyInt rhs);
the expression
1 + MyInt(2)
is lowered to
operator+(MyInt(1), MyInt(2))
> so why wasn't this introduced in D also?
My guess is that there is no implicit construction of objects
in D anyway so there wouldn't be that benefit.
Ali
It's also preferred (at least by me) because such methods don't
have to be in a class/struct and blows it up. They don't effect
the class/struct and thanks to UFCS we still could call them
like member methods.
So IMO because they have no effect in a class/struct they
shouldn't be there.
Compare:
bool opEquals(ref const A a) { ... } inside of struct A
versus:
bool opEquals(ref const A lhs, ref const A rhs) { ... }
I would prefer the last one.
But I would like to see an official thread for this, if any
exist. Do you know one? I'm just startled that D follows this
way. :)
The possibility of static operator was raised, specifically for
opDollar, in std.range, for the possibility of it automatically
resolving to length.
Reception for *just* this was kind of cold. I remember it being
downright hostile for UFCS operators in general.
The full conversation is here:
http://d.puremagic.com/issues/show_bug.cgi?id=7177
Note that while UFCS was discussed, it wasn't the root of the
discussion :/
