safe method overloading with different refness of its arguments

[drug via Digitalmars-d-learn]

```
struct Foo
{
     ubyte width, length;

     // by reference
     bool opEquals(ref const(Foo) other) const pure @safe
     {
         if (width != other.width)
             return false;
         if (length != other.length)
             return false;
	return true;
     }

     // by value
     bool opEquals(const(Foo) other) const pure @safe
     {
         return opEquals(other);
     }
}
```

It works for me, but I'm curious - will compiler always recognize what 
to call and I can avoid recursion and stack overflow or I shouldn't do so?