Compiled using DMD 2.007 on Windows.

int delegate() foo(){
	int a = 30;
	int b = 60;
	int c = 90;

	int one(){ return a; }
	int two(){ return b; }

	writefln(&a);
	writefln(&b);
	writefln(&c);

	return &one;
}

version(Windows) void main(){
	foo();
}

Prints:
8B2FF4
8B2FF8
12FF28

This means that variable 'b' is being allocated on the heap, even though nested function 'two' is never referenced.