class opBinary overloading. value + null and null + value

[cal]

On Sunday, 21 October 2012 at 20:54:15 UTC, ref2401 wrote:
> On Sunday, 21 October 2012 at 20:42:08 UTC, cal wrote:
>> On Sunday, 21 October 2012 at 20:34:51 UTC, ref2401 wrote:
>>> what should i do to make my binary operation commutative?

> in the following case
>
> auto v5 = v1 + v2;
>
> there will be compile time error:
> overloads pure @safe MyClass(MyClass rhs) and pure @safe 
> MyClass(MyClass lhs) both match argument list for opBinary		

Oh right, sorry. Well if all you want to do is catch the null on 
either side of the '+', you could use this overload of 
opBinaryRight:

MyClass opBinaryRight(string op: "+", T)(T rhs) if (!is(T == 
MyClass))
{			
   return null;	
}

I'm not sure if this is what you are trying to do though...