Operators overloading in D2 again

[Robert Clipsham]

On 02/05/10 07:14, Dan wrote:
> Hi everyone,
>
> is there anyway to do this with operators overloading? :

The following code does it:
----
class Tester
{
         double x = 0.0;

         T opBinary(string op:"+", T)(T value) if(is(T : double))
         {
                 return x+value;
         }

         T opBinary(string op:"+", T)(T other) if(is(T : Tester))
         {
                 Tester ret = new Tester;
                 ret.x = this.x + other.x;
                 return ret;
         }
}

int main(char[][] args)
{
         Tester t1 = new Tester;
         Tester t2 = new Tester;

         t1.x = 1.0;
         t2.x = 2.0;

         Tester t3 = new Tester;
         t3 = t1+t2;
         assert (t3.x == 3.0);

         return 0;
}
----

Some variations from the original code:

  - Fixed the assert ==, not =
  - Made sure all testers are initialised... Don't forget to instantiate 
classes before you use them, otherwise you'll end up with segmentation 
faults
  - Fixed a semantic error in the latter of the binary functions - an 
empty Tester is at 0, if you want to add them you need to make sure you 
do that, not just add other

I'd also advise you replace Tester with a struct if you won't be needing 
inheritance, this way you save some memory overhead, and don't have to 
remember to use = new Tester; Hope this helps :)