I have two optimization suggestions: perhaps not part of the language design.

1. If an object is created in a function scope (with new), but the pointer to that object is never copied into an outside object, it automatically becomes an auto object.  This might be difficult to detect in some cases, but not doing the optimization is harmless.

Example:

foo(char[] s)
{
char[] xyz = "hello, " ~ s;
char[] b = xyz ~ "\0";

//(possibly use or store b somewhere)
}

Since the pointer to xyz is never put in an object, it can become "auto".

2. Object absorbtion:

In a similar way, objects that are never passed out of a class could be absorbed:

class rectangle {
int area() {return a*b;}
int a = 5;
int b = 7;
};

int foo()
{
rectangle r = new rectangle;

return r.area();
}

Would be equivalent to:

int foo()
{
int r_a = 5;
int r_b = 7;
return r_a * r_b;
}

. opening the door to more optimizations, without putting referenced objects on the stack.  These opts are restricted in a similar way to "register" vars, i.e. taking the address conflicts with optimization.

Kevin