Merge pull request #3 from uuttff8/master

Add "minus" function for negative dimension target constant value

Author: Ernest0-Production

Sources/DeclarativeLayoutKit/AutoLayout/Anchor/BidirectionalDimensionAutoLayoutAnchor.swift

@@ -56,4 +56,12 @@ public extension BidirectionalDimensionAutoLayoutAnchorConvertible {
 
         return copy
     }
+    
+    func minus(_ constant: CGFloat) -> BidirectionalDimensionAutoLayoutAnchor {
+        var copy = asBidirectionalDimensionAutoLayoutAnchor()
+        
+        copy.constant = -constant
+        
+        return copy
+    }
 }

Sources/DeclarativeLayoutKit/AutoLayout/Anchor/DimensionAutoLayoutAnchor.swift

@@ -56,4 +56,12 @@ public extension DimensionAutoLayoutAnchorConvertible {
 
         return copy
     }
+    
+    func minus(_ constant: CGFloat) -> DimensionAutoLayoutAnchor {
+        var copy = asDimensionAutoLayoutAnchor()
+        
+        copy.constant = -constant
+        
+        return copy
+    }
 }