How do I use the ScopedAllocator?

[Yuxuan Shui via Digitalmars-d]

Is it OK to use makeArray with ScopedAllocator to allocate 
something with a destructor?

Because the destructor is not called when ScopedAllocator goes 
out of scope. And if I manually call dispose, I get a double free 
error:

	struct A {
		int a;

		~this() nothrow {
		}
	}
	void test(){
		import std.experimental.allocator.mallocator : Mallocator;
		import 
std.experimental.allocator.building_blocks.scoped_allocator : 
ScopedAllocator;
		import std.experimental.allocator;
		ScopedAllocator!Mallocator alloc;

		auto b = alloc.makeArray!A(10, A(1));
		auto c = alloc.makeArray!A(2, A(2));


		alloc.dispose(b);
		alloc.dispose(c);

	}

	void main() {
		test();
	}