diff --git a/Source/Constraint.swift b/Source/Constraint.swift
index 6a91fee..953b1fd 100644
--- a/Source/Constraint.swift
+++ b/Source/Constraint.swift
@@ -313,7 +313,7 @@ final public class Constraint {
                 NSException(name: "Cannot Install Constraint", reason: "Already installed on different view.", userInfo: nil).raise()
                 return []
             }
-            return (self.installedLayoutConstraints?.allObjects as? Array<LayoutConstraint>)!
+            return self.installedLayoutConstraints?.allObjects as! Array<LayoutConstraint>
         }
         
         var newLayoutConstraints = Array<LayoutConstraint>()
@@ -465,9 +465,9 @@ final public class Constraint {
     
     private func constrainTo(other: ConstraintItem, relation: ConstraintRelation) -> Constraint {
         if other.attributes != ConstraintAttributes.None {
-            var toLayoutAttributes = other.attributes.layoutAttributes
+            let toLayoutAttributes = other.attributes.layoutAttributes
             if toLayoutAttributes.count > 1 {
-                var fromLayoutAttributes = self.fromItem.attributes.layoutAttributes
+                let fromLayoutAttributes = self.fromItem.attributes.layoutAttributes
                 if toLayoutAttributes != fromLayoutAttributes {
                     NSException(name: "Invalid Constraint", reason: "Cannot constrain to multiple non identical attributes", userInfo: nil).raise()
                     return self
@@ -509,22 +509,22 @@ final public class Constraint {
     }
     
     private class func closestCommonSuperviewFromView(fromView: View?, toView: View?) -> View? {
-        var views = NSMutableSet()
+        var views = Set<View>()
         var fromView = fromView
         var toView = toView
         do {
             if let view = toView {
-                if views.containsObject(view) {
+                if views.contains(view) {
                     return view
                 }
-                views.addObject(view)
+                views.insert(view)
                 toView = view.superview
             }
             if let view = fromView {
-                if views.containsObject(view) {
+                if views.contains(view) {
                     return view
                 }
-                views.addObject(view)
+                views.insert(view)
                 fromView = view.superview
             }
         } while (fromView != nil || toView != nil)
diff --git a/Source/ConstraintItem.swift b/Source/ConstraintItem.swift
index ea811a5..f9f7c04 100644
--- a/Source/ConstraintItem.swift
+++ b/Source/ConstraintItem.swift
@@ -41,22 +41,12 @@ final public class ConstraintItem {
     internal var attributes: ConstraintAttributes
     
     internal var view: View? {
-        get {
-            if let view = self.object as? View {
-                return view
-            }
-            return nil
-        }
+        return self.object as? View
     }
     
     #if os(iOS)
     internal var layoutSupport: UILayoutSupport? {
-        get {
-            if let layoutSupport = self.object as? UILayoutSupport {
-                return layoutSupport
-            }
-            return nil
-        }
+        return self.object as? UILayoutSupport
     }
     #endif
 }
diff --git a/Source/ConstraintMaker.swift b/Source/ConstraintMaker.swift
index c226064..f9b4af3 100644
--- a/Source/ConstraintMaker.swift
+++ b/Source/ConstraintMaker.swift
@@ -61,13 +61,13 @@ final public class ConstraintMaker {
         return constraint
     }
     
-    internal class func prepareConstraints(view: View, block: (make: ConstraintMaker) -> Void) -> Array<Constraint> {
+    internal class func prepareConstraints(view: View, @noescape block: (make: ConstraintMaker) -> Void) -> Array<Constraint> {
         let maker = ConstraintMaker(view: view)
         block(make: maker)
         return maker.constraints
     }
     
-    internal class func makeConstraints(view: View, block: (make: ConstraintMaker) -> Void) {
+    internal class func makeConstraints(view: View, @noescape block: (make: ConstraintMaker) -> Void) {
         #if os(iOS)
         view.setTranslatesAutoresizingMaskIntoConstraints(false)
         #else
@@ -80,7 +80,7 @@ final public class ConstraintMaker {
         }
     }
     
-    internal class func remakeConstraints(view: View, block: (make: ConstraintMaker) -> Void) {
+    internal class func remakeConstraints(view: View, @noescape block: (make: ConstraintMaker) -> Void) {
         #if os(iOS)
         view.setTranslatesAutoresizingMaskIntoConstraints(false)
         #else
@@ -99,7 +99,7 @@ final public class ConstraintMaker {
         }
     }
     
-    internal class func updateConstraints(view: View, block: (make: ConstraintMaker) -> Void) {
+    internal class func updateConstraints(view: View, @noescape block: (make: ConstraintMaker) -> Void) {
         #if os(iOS)
         view.setTranslatesAutoresizingMaskIntoConstraints(false)
         #else
diff --git a/Source/View+Snap.swift b/Source/View+Snap.swift
index 103e8d6..749799c 100644
--- a/Source/View+Snap.swift
+++ b/Source/View+Snap.swift
@@ -68,19 +68,19 @@ public extension View {
     final public var snp_centerWithinMargins: ConstraintItem { return ConstraintItem(object: self, attributes: ConstraintAttributes.CenterWithinMargins) }
     #endif
     
-    final public func snp_prepareConstraints(block: (make: ConstraintMaker) -> Void) -> [Constraint] {
+    final public func snp_prepareConstraints(@noescape block: (make: ConstraintMaker) -> Void) -> [Constraint] {
         return ConstraintMaker.prepareConstraints(self, block: block)
     }
     
-    final public func snp_makeConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_makeConstraints(@noescape block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.makeConstraints(self, block: block)
     }
     
-    final public func snp_updateConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_updateConstraints(@noescape block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.updateConstraints(self, block: block)
     }
     
-    final public func snp_remakeConstraints(block: (make: ConstraintMaker) -> Void) {
+    final public func snp_remakeConstraints(@noescape block: (make: ConstraintMaker) -> Void) {
         ConstraintMaker.remakeConstraints(self, block: block)
     }
     
@@ -103,4 +103,4 @@ public extension View {
     }
 }
 
-private var installedLayoutConstraintsKey = ""
\ No newline at end of file
+private var installedLayoutConstraintsKey = ""