Split the pager class into two

I've also made the base class abstract, and the derived class a template.
Hopefully this'll let me work on different parts of the class without
major issues.

This code compiles, but since it's incomplete, I can't test it properly.

common/map/region_pager.hpp

@@ -26,31 +26,67 @@
 
 #include <list>
 
-class RegionPager {
+class RegionPagerBase {
 public:
-	RegionPager() = delete;
-	RegionPager(int regionWidth, int regionHeight, int regionDepth);
-	~RegionPager();
+	RegionPagerBase() = delete;
+	RegionPagerBase(int regionWidth, int regionHeight, int regionDepth);
+	~RegionPagerBase();
 
 	int SetTile(int x, int y, int z, int v);
 	int GetTile(int x, int y, int z);
 
+	void Update();
+
 	Region* GetRegion(int x, int y);
 
-	void LoadRegion(int x, int y);
-	void SaveRegion(int x, int y);
-	void CreateRegion(int x, int y);
-	void UnloadRegion(int x, int y);
+	//interface
+	virtual Region* LoadRegion(int x, int y) = 0;
+	virtual Region* SaveRegion(int x, int y) = 0;
+	virtual Region* CreateRegion(int x, int y) = 0;
+	virtual void UnloadRegion(int x, int y) = 0;
 
 	//accessors
 	int GetRegionWidth() { return regionWidth; }
 	int GetRegionHeight() { return regionHeight; }
 	int GetRegionDepth() { return regionDepth; }
-private:
+protected:
 	const int regionWidth;
 	const int regionHeight;
 	const int regionDepth;
 	std::list<Region> regionList;
 };
 
+template<typename MapGenerator, typename MapFileFormat>
+class RegionPager : public RegionPagerBase {
+public:
+	Region* LoadRegion(int x, int y) {
+		//TODO
+		//if there's no region to load, return null
+	}
+
+	Region* SaveRegion(int x, int y) {
+		//TODO
+		//save the region using the functor
+	}
+
+	Region* CreateRegion(int x, int y) {
+		//TODO
+		//create the region
+		//DON'T call this on a non-zero region,
+		//or if there's a region saved to the disk
+	}
+
+	void UnloadRegion(int x, int y) {
+		//TODO
+		//free the region, possibly saving it
+	}
+
+	//accessors
+	MapGenerator* GetGenerator() { return &generator; }
+	MapFileFormat* GetFormat() { return &format; }
+protected:
+	MapGenerator generator;
+	MapFileFormat format;
+};
+
 #endif