writing efficient struct operators

[blevin]

I noticed that dmd generates implicit checks for a NULL "this" argument 
in overloaded struct operators.  Assuming my operator does not modify 
its arguments, including "this", is there a way to avoid that cost?

Putting the equivalent code in a static member function with "in" 
arguments avoids the cost but gives up the nice syntax.  The struct in 
question is a vector, so it'd be nice to provide operators.

Perhaps D2.0's invariant keyword address this?  (There doesn't seem to 
be a released D2.0 compiler for linux yet, so I haven't checked.)

   struct Vec3d
   {
       double x=0, y=0, z=0;

       Vec3d opAdd(Vec3d rhs) {
           // Note: implicit assert(this != NULL) inserted here.
           // Would marking this method 'invariant' help?
           return Vec3d(x+rhs.x, y+rhs.y, z+rhs.z);
       }

       static Vec3d Add(in Vec3d a, in Vec3d b) {
           // Static method avoids the assert
           return Vec3d(a.x+b.x, a.y+b.y, a.z+b.z);
       }

       static Vec3d opCall(double x, double y, double z) {
           Vec3d v;
           v.x = x;
           v.y = y;
           v.z = z;
           return v;
       }
   }

thanks,
--
Brett.