Anyone know why this CTFE isn't working?

[Rory McGuire]

Sorry about the html

On Fri, 16 Jul 2010 11:46:48 +0200, Rory McGuire <rmcguire at neonova.co.za>  
wrote:
>
> import std.stdio;
>
> struct State {
> 	string s; string getString() { return s; }
> 	static State opCall(string s) {
> 		State ret;
> 		ret.s = s;
> 		return ret;
> 	}
> }
>
> void main() {
> 	auto s = State("adf");
> 	pragma(msg, s.getString());
> }
>
> dmd Output: (line 14 is the pragma statement)
>
> struct.d(14): Error: variable s cannot be read at compile time
> struct.d(14): Error: cannot evaluate s.getString() at compile time
> s.getString()