Automatically using stack allocations instead of GC

[Per Nordlöw]

Are there any plans (or is it already happening) to make 
D-compilers automatically use stack allocations when possible in 
cases like

int foo()
{
     auto x = [1, 2]; // should be allocated on the stack
     return y = x[0] + x[1];
}

where allocations are "small enough" and cannot escape the 
current scope?

And how does/should/will this interact with `@nogc`?