How do you deal with scoped allocations?

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On Sunday, 8 December 2013 at 00:17:48 UTC, Adam D. Ruppe wrote:
> On Sunday, 8 December 2013 at 00:16:46 UTC, Adam D. Ruppe wrote:
>> the same general pattern there of static array up to a certain 
>> size.
>
> static array being "T[max_size]", not "static T[max_size]"
>
> just so it uses the stack for most things.

So rather something like this:
----
import std.stdio;

struct Helper(T, uint StackSize = 128) {
	T[StackSize] buffer = void;

	T[] allocate(size_t n) {
		if (n <= StackSize)
			return buffer[0 .. n];

		return new T[n];
	}
}

void main() {
	auto h = Helper!int();

	int[] arr = h.allocate(512);
}
----

Yes? I don't like it, because it isn't a one liner. Isn't it 
possible in one line?
A personal dream of me would be: scope int[] arr = new int[n]; or 
the implementation of DIP46. :)