BShape: add move construction and assignment support

GCC 2 support is also provided with `MoveFrom` method.

Change-Id: Ifedaf0b1406a5a2cb6bf3465249cea0f360e06d6
Reviewed-on: https://review.haiku-os.org/c/haiku/+/8531
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: waddlesplash <[email protected]>

headers/os/interface/Shape.h

@@ -50,6 +50,9 @@ class BShape : public BArchivable {
 public:
 								BShape();
 								BShape(const BShape& other);
+#if defined(__cplusplus) && __cplusplus >= 201103L
+								BShape(BShape&& other);
+#endif
 								BShape(BMessage* archive);
 	virtual						~BShape();
 
@@ -58,11 +61,15 @@ public:
 									bool deep = true) const;
 
 			BShape&				operator=(const BShape& other);
+#if defined(__cplusplus) && __cplusplus >= 201103L
+			BShape&				operator=(BShape&& other);
+#endif
 
 			bool				operator==(const BShape& other) const;
 			bool				operator!=(const BShape& other) const;
 
 			void				Clear();
+			void				MoveFrom(BShape& other);
 			BRect				Bounds() const;
 			BPoint				CurrentPosition() const;
 

src/kits/interface/Shape.cpp

@@ -143,6 +143,15 @@ BShape::BShape(const BShape& other)
 }
 
 
+#if defined(__cplusplus) && __cplusplus >= 201103L
+BShape::BShape(BShape&& other)
+{
+	InitData();
+	MoveFrom(other);
+}
+#endif
+
+
 BShape::BShape(BMessage* archive)
 	:
 	BArchivable(archive)
@@ -250,6 +259,17 @@ BShape::operator=(const BShape& other)
 }
 
 
+#if defined(__cplusplus) && __cplusplus >= 201103L
+BShape&
+BShape::operator=(BShape&& other)
+{
+	MoveFrom(other);
+
+	return *this;
+}
+#endif
+
+
 bool
 BShape::operator==(const BShape& other) const
 {
@@ -303,6 +323,20 @@ BShape::Clear()
 }
 
 
+void
+BShape::MoveFrom(BShape& other)
+{
+	fState = other.fState;
+	fBuildingOp = other.fBuildingOp;
+
+	shape_data* data = (shape_data*)fPrivateData;
+	fPrivateData = other.fPrivateData;
+	other.fPrivateData = data;
+
+	other.Clear();
+}
+
+
 BRect
 BShape::Bounds() const
 {