a lottt of stuff

Project Reboot 3.0/SparseArray.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include "Array.h"
+#include "BitArray.h"
+
+template <typename ElementType>
+union TSparseArrayElementOrListLink
+{
+    TSparseArrayElementOrListLink(ElementType& InElement)
+        : ElementData(InElement)
+    {
+    }
+    TSparseArrayElementOrListLink(ElementType&& InElement)
+        : ElementData(InElement)
+    {
+    }
+
+    TSparseArrayElementOrListLink(int32 InPrevFree, int32 InNextFree)
+        : PrevFreeIndex(InPrevFree)
+        , NextFreeIndex(InNextFree)
+    {
+    }
+
+    TSparseArrayElementOrListLink<ElementType> operator=(const TSparseArrayElementOrListLink<ElementType>& Other)
+    {
+        return TSparseArrayElementOrListLink(Other.NextFreeIndex, Other.PrevFreeIndex);
+    }
+
+    /** If the element is allocated, its value is stored here. */
+    ElementType ElementData;
+
+    struct
+    {
+        /** If the element isn't allocated, this is a link to the previous element in the array's free list. */
+        int PrevFreeIndex;
+
+        /** If the element isn't allocated, this is a link to the next element in the array's free list. */
+        int NextFreeIndex;
+    };
+};
+
+template <typename ArrayType>
+class TSparseArray
+{
+public:
+    typedef TSparseArrayElementOrListLink<ArrayType> FSparseArrayElement;
+
+    TArray<FSparseArrayElement> Data;
+    TBitArray AllocationFlags;
+    int32 FirstFreeIndex;
+    int32 NumFreeIndices;
+};