Compiler bug? (alias sth this; and std.signals)

[Joe]

Ok, i was trying out D and wanted to see if i could create 
something that behaves like a property but adds a change 
notification signal. Doing this, I encountered a hangup which 
might be a bug. So far I have the following:

-----------------------------------------------------------

import std.signals;
import std.stdio;

struct Property
{
	alias get this;
	
	int set(int v) { emit(); return data_ = v; }
	int get() { return data_; }
	
	int opAssign(int v) { return set(v); }
	
	mixin Signal!();

private:
	int data_ = 0;
}

struct Foo
{
	Property prop;
}

class Observer
{
	void watch()
	{
		writeln("Value change observed!");
	}
}

-----------------------------------------------------------

This works:
void main()
{
	Foo f;
	Observer o = new Observer;
	f.prop.connect(&o.watch);
	f.prop = 7;
}

This also works:
void main()
{
	Foo f;
	Observer o = new Observer;
	f.prop = 7;
	writeln(f.prop);
}

This never terminates:
void main()
{
	Foo f;
	Observer o = new Observer;
	f.prop.connect(&o.watch);
	f.prop = 7;
	writeln(f.prop);
}