CGRect special values implemented

Author: bubski

Foundation/NSGeometry.swift

@@ -227,6 +227,18 @@ extension CGRect {
     }
 }
 
+extension CGRect {
+    public static let null = CGRect(x: CGFloat.infinity,
+                                    y: CGFloat.infinity,
+                                    width: CGFloat(0),
+                                    height: CGFloat(0))
+    
+    public static let infinite = CGRect(x: -CGFloat.greatestFiniteMagnitude / 2,
+                                        y: -CGFloat.greatestFiniteMagnitude / 2,
+                                        width: CGFloat.greatestFiniteMagnitude,
+                                        height: CGFloat.greatestFiniteMagnitude)
+}
+
 extension CGRect: Equatable {
     public static func ==(lhs: CGRect, rhs: CGRect) -> Bool {
         return lhs.origin == rhs.origin && lhs.size == rhs.size

TestFoundation/TestNSGeometry.swift

@@ -32,6 +32,7 @@ class TestNSGeometry : XCTestCase {
             ("test_CGSize_ExtendedConstruction", test_CGSize_ExtendedConstruction),
             ("test_CGRect_BasicConstruction", test_CGRect_BasicConstruction),
             ("test_CGRect_ExtendedConstruction", test_CGRect_ExtendedConstruction),
+            ("test_CGRect_SpecialValues", test_CGRect_SpecialValues),
             ("test_NSEdgeInsets_BasicConstruction", test_NSEdgeInsets_BasicConstruction),
             ("test_NSEdgeInsetsEqual", test_NSEdgeInsetsEqual),
             ("test_NSMakePoint", test_NSMakePoint),
@@ -195,6 +196,20 @@ class TestNSGeometry : XCTestCase {
         XCTAssertEqual(r4.size.width, CGFloat(3))
         XCTAssertEqual(r4.size.height, CGFloat(4))
     }
+    
+    func test_CGRect_SpecialValues() {
+        let r1 = CGRect.null
+        XCTAssertEqual(r1.origin.x, CGFloat.infinity)
+        XCTAssertEqual(r1.origin.y, CGFloat.infinity)
+        XCTAssertEqual(r1.size.width, CGFloat(0.0))
+        XCTAssertEqual(r1.size.height, CGFloat(0.0))
+        
+        let r2 = CGRect.infinite
+        XCTAssertEqual(r2.origin.x, -CGFloat.greatestFiniteMagnitude / 2)
+        XCTAssertEqual(r2.origin.y, -CGFloat.greatestFiniteMagnitude / 2)
+        XCTAssertEqual(r2.size.width, CGFloat.greatestFiniteMagnitude)
+        XCTAssertEqual(r2.size.height, CGFloat.greatestFiniteMagnitude)
+    }
 
     func test_NSEdgeInsets_BasicConstruction() {
         let i1 = NSEdgeInsets()