How to initialize static arrays with variable data

[Steven Schveighoffer]

In another thread, Don (and others including myself) advocate that an  
array literal should be an immutable array.  This has benefits when you  
want to use immutable arrays that have statically determined values.  It  
means you don't require heap allocations when assigning an immutable  
array, just like strings are handled.

The point was brought up by Walter (and previously by others), "what about  
initializing non-immutable arrays with runtime-determined data?"

i.e.

int[] x = [a, b, c];

The answer is simply, use a library function to allocate the array on the  
heap.

i.e.

int[] x = toArray(a, b, c);

This works great, but there is still one missing piece that was pointed  
out by Denis Koroshin and grauzone.  What about static arrays that you  
*don't* want to initialize on the heap?

i.e.

int[3] x = [a, b, c];

Currently, the act of making an array literal allocates on the heap.  If  
array literals become immutable, then you can't do [a, b, c] because it is  
determined at runtime.  So how can this be made to work?  Should it be a  
library function?

i.e.

int[3] x = toStatic(a, b, c);

Or should the compiler do something magic, such as type array literals  
with runtime values in them as a static array?  It would be nice to allow  
this:

int[3] x = [a, b, c];

but then to be safe (so you cannot easily construct an escaping array) you  
cannot allow this:

int[] x = [a, b, c];

Any other ideas?  I think this problem really needs a solution if we are  
going to address array literals.

-Steve