Codechange: make explicit when a TileIndex is cast to its basetype (#11190)

This prevents people accidentially assigning a TileIndex to a Date
or any other type they shouldn't.

src/window_gui.h

@@ -284,6 +284,12 @@ public:
 	void CreateNestedTree(bool fill_nested = true);
 	void FinishInitNested(WindowNumber window_number = 0);
 
+	template<typename T, std::enable_if_t<std::is_base_of<StrongTypedefBase, T>::value, int> = 0>
+	void FinishInitNested(T number)
+	{
+		this->FinishInitNested(static_cast<typename T::BaseType>(number));
+	}
+
 	/**
 	 * Set the timeout flag of the window and initiate the timer.
 	 */
@@ -880,6 +886,12 @@ public:
 Window *BringWindowToFrontById(WindowClass cls, WindowNumber number);
 Window *FindWindowFromPt(int x, int y);
 
+template<typename T, std::enable_if_t<std::is_base_of<StrongTypedefBase, T>::value, int> = 0>
+Window *BringWindowToFrontById(WindowClass cls, T number)
+{
+	return BringWindowToFrontById(cls, static_cast<typename T::BaseType>(number));
+}
+
 /**
  * Open a new window.
  * @tparam Wcls %Window class to use if the window does not exist.