struct Note
{
	string topic;
	string content;
}

class NoteStore
{	
	
	Note[][string] store;
	
	static Note[0] empty;
	
	Note[] getNotes(string id)
	{
		return (id in store) ? store[id] : empty;
	}	
}

void main() {}


dmd ns.d

 OPTLINK (R) for Win32  Release 8.00.17
 Copyright (C) Digital Mars 1989-2013  All rights reserved.
 http://www.digitalmars.com/ctg/optlink.html
 ns.obj(ns)  Offset 00678H Record Type 009D
  Error 16: Index Range
 --- errorlevel 1

dmd --version
DMD32 D Compiler v2.071.0
Copyright (c) 1999-2015 by Digital Mars written by Walter Bright