Linker Errors when Constructing an Immutable Struct

[Adam Wilson via Digitalmars-d]

Please consider the following code:

module aurora.immediate.input;

public enum Key : int { //... }

public immutable struct KeyData
{
	private Key _key;
	@property public Key KeyCode() { return _key; }

	private bool _isDown;
	@property public bool IsDown() { return _isDown; }

	private bool _isUp;
	@property public bool IsUp() { return _isUp; }

	private bool _isRepeating;
	@property public bool IsRepeating() { return _isRepeating; }

	@disable this();

	public immutable this(Key key, bool isDown, bool isUp, bool isRepeating =  
false) nothrow
	{
		_key = key;
		_isDown = isDown;
		_isUp = isUp;
		_isRepeating = isRepeating;
	}
}

module aurora.immediate.window;
import aurora.immediate.input;

public class Window {
protected void delegate(immutable(KeyData) args) nothrow onKeyDown;
private LRESULT internalWndProc(HWND hwnd, UINT message, WPARAM wParam,  
LPARAM lParam) nothrow {
	if (onKeyDown !is null) onKeyDown(immutable KeyData(cast(Key)wParam,  
true, false, false));
	return 0;
}
}

When compiled and imported as a static library it fails to compile with  
the following linker errors:
libaurora_immediate64d.lib(window_47a_278.obj) : error LNK2019: unresolved  
external symbol _D6aurora9immediate5input7KeyData6__initZ referenced in  
function _D6aurora9immediate6window6Window15internalWndProcMFNbPvkmlZl
libaurora_immediate64d.lib(window_47a_278.obj) : error LNK2019: unresolved  
external symbol  
_D6aurora9immediate5input7KeyData6__ctorMyFNbNcE6aurora9immediate5input3KeybbbZyS6aurora9immediate5input7KeyData  
referenced in function  
_D6aurora9immediate6window6Window15internalWndProcMFNbPvkmlZl

It appears that the linker cannot find .init and the .ctor. Is this a  
compiler bug or am I doing something wrong? I am wondering if this is a  
problem with immutable structs? Any pointers would be very appreciated.

-- 
Adam Wilson
GitHub/IRC: LightBender
Aurora Project Coordinator