1 files changed, 6 insertions, 4 deletions

diff --git a/src/UI/Window.h b/src/UI/Window.h
index d7a29dc47..f2023c731 100644
--- a/src/UI/Window.h
+++ b/src/UI/Window.h
@@ -1,4 +1,4 @@
-
+
 // Window.h
 
 // Interfaces to the cWindow class representing a UI window for a specific block
@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include <functional>
 #include "../ItemGrid.h"
 
 
@@ -31,7 +32,8 @@ class cWorld;
 
 typedef std::list<cPlayer *> cPlayerList;
 typedef std::vector<cSlotArea *> cSlotAreas;
-
+using cPlayerListCallback   = std::function<bool(cPlayer       &)>;
+using cClientHandleCallback = std::function<bool(cClientHandle &)>;
 
 
 
@@ -151,10 +153,10 @@ public:
 	void OwnerDestroyed(void);
 
 	/** Calls the callback safely for each player that has this window open; returns true if all players have been enumerated */
-	bool ForEachPlayer(cItemCallback<cPlayer> & a_Callback);
+	bool ForEachPlayer(const cPlayerListCallback & a_Callback);
 
 	/** Calls the callback safely for each client that has this window open; returns true if all clients have been enumerated */
-	bool ForEachClient(cItemCallback<cClientHandle> & a_Callback);
+	bool ForEachClient(cClientHandleCallback & a_Callback);
 
 	/** Called on shift-clicking to distribute the stack into other areas; Modifies a_ItemStack as it is distributed!
 	if a_ShouldApply is true, the changes are written into the slots;