> For values with compiler-visible scoped lifetime, the compiler will automatically promote them to stack variables. There is currently no way to enforce this happening, but it would be perfectly possible to add such an annotation.

Other languages such as Java have that optimization too. But it is quite limited because it can only be applied to data whose size is known at compile-time. There is also the problem that if some data allocated in a procedure is passed to another procedure, it can't be allocated on the stack because it can escape.

A programmer working in a low-level language can be smart and choose the best locations (stack or heap) for each piece of data. A language that does not allow explicit stack access (like C does), can never make as optimal decisions.