ItemStack ctor stuff

libswan/include/swan/ItemStack.h

@@ -6,7 +6,7 @@ class Item;
 
 class ItemStack {
 public:
-	ItemStack(Item *item, int count = 0): item_(item), count_(count) {
+	ItemStack(Item *item, int count): item_(item), count_(count) {
 
 		// We don't want a "partially empty" state.
 		if (item == nullptr || count == 0) {
@@ -15,6 +15,8 @@ public:
 		}
 	}
 
+	ItemStack(): item_(nullptr), count_(0) {}
+
 	Item *item() { return item_; }
 	int count() { return count_; }
 	bool empty() { return item_ == nullptr; }