stuck on opDiv / opBinary

[Timon Gehr via Digitalmars-d-learn]

On 08/30/2015 07:02 PM, Spacen Jasset wrote:
> I have just added an opDiv to this class, but it doesn't seem to pick it
> up.
> math/vector.d(30): Error: 'this /= mag' is not a scalar, it is a Vector3
>
> I can't see why that is, becuase my opMul works in the same place. Can
> anyone point out what I have done wrong?
> ...

import std.math: sqrt;
import std.algorithm: map,sum,canFind;

struct Vector3{
     float[3] xyz;
     void normalise(){ this/=magnitude();  }
     float magnitude(){ return sqrt(xyz[].map!(a=>a*a).sum); }
     enum scalarOps=["*","/"];
     enum isScalarOp(string op)=scalarOps.canFind(op);
     void scalar(string op)(float scalar)if(isScalarOp!op){
         foreach(ref a;xyz) mixin(`a `~op~`=scalar;`);
     }
     Vector3 opBinary(string op)(float scalar)if(isScalarOp!op){
         Vector3 v=this;
         v.scalar!op(scalar);
         return v;
     }
     auto opOpAssign(string op)(float rhs)if(isScalarOp!op){
         return mixin(`this=this `~op~` rhs`);
     }
}