diff --git a/Sources/Algorithm+Array.swift b/Sources/Algorithm+Array.swift
index 86757cc..50ae78a 100644
--- a/Sources/Algorithm+Array.swift
+++ b/Sources/Algorithm+Array.swift
@@ -37,10 +37,7 @@ extension Array where Element: Equatable {
      */
     @discardableResult
     mutating func remove(object: Element) -> Element? {
-        guard let v = index(of: object) else {
-            return nil
-        }
-        return remove(at: v)
+      return index(of: object).map { self.remove(at: $0) }
 	}
 
     /**
@@ -82,10 +79,8 @@ extension Array where Element: Equatable {
     public func count(of elements: [Element]) -> Int {
 		var c = 0
         for e in elements {
-            for x in self {
-                if e == x {
-                    c += 1
-                }
+            for x in self where e == x {
+                c += 1
             }
         }
 		return c
diff --git a/Sources/DoublyLinkedList.swift b/Sources/DoublyLinkedList.swift
index 961a1bc..1a6e524 100644
--- a/Sources/DoublyLinkedList.swift
+++ b/Sources/DoublyLinkedList.swift
@@ -167,11 +167,10 @@ public struct DoublyLinkedList<Element>: CustomStringConvertible, Sequence {
     public func makeIterator() -> DoublyLinkedList.Iterator {
         var it = head
         return AnyIterator {
-            guard let e = it?.element else {
-                return nil
-            }
+          defer {
             it = it?.next
-            return e
+          }
+          return it?.element
 		}
 	}
 
diff --git a/Sources/RedBlackTree.swift b/Sources/RedBlackTree.swift
index 36e1c7c..e4f175e 100644
--- a/Sources/RedBlackTree.swift
+++ b/Sources/RedBlackTree.swift
@@ -75,15 +75,7 @@ public struct RedBlackTree<Key: Comparable, Value>: Probable, Collection, Custom
 		- returns:	String
 	*/
 	public var description: String {
-        var output = "["
-        let l = count - 1
-        for i in 0..<count {
-            output += "\(self[i])"
-            if i != l {
-                output += ", "
-            }
-        }
-        return output + "]"
+        return "[" + map { "\($0)" }.joined(separator: ", ") + "]"
 	}
 
 	/**
@@ -166,15 +158,8 @@ public struct RedBlackTree<Key: Comparable, Value>: Probable, Collection, Custom
 	//	:returns:	RedBlackTree.Generator
 	//
 	public func makeIterator() -> RedBlackTree.Iterator {
-        var index = startIndex
-        return AnyIterator {
-            if index < self.endIndex {
-                let i: Int = index
-                index += 1
-                return self[i]
-            }
-            return nil
-        }
+        var i = indices.makeIterator()
+        return AnyIterator { i.next().map { self[$0] } }
 	}
 
 	/**
diff --git a/Sources/SortedDictionary.swift b/Sources/SortedDictionary.swift
index fd75e0d..901d31e 100644
--- a/Sources/SortedDictionary.swift
+++ b/Sources/SortedDictionary.swift
@@ -89,20 +89,12 @@ public struct SortedDictionary<Key: Comparable, Value>: Probable, Collection, Eq
 	
 	/// Retrieves an Array of the key values in order.
 	public var keys: [Key] {
-		var s = [Key]()
-		for x in self {
-			s.append(x.key)
-		}
-		return s
+		return map { $0.key }
 	}
 	
 	/// Retrieves an Array of the values that are sorted based
 	public var values: [Value] {
-		var s = [Value]()
-		for x in self {
-			s.append(x.value!)
-		}
-		return s
+		return flatMap { $0.value }
 	}
 	
 	/// Initializer.
@@ -128,15 +120,8 @@ public struct SortedDictionary<Key: Comparable, Value>: Probable, Collection, Eq
 	}
 	
 	public func makeIterator() -> SortedDictionary.Iterator {
-		var index = startIndex
-        return AnyIterator {
-			if index < self.endIndex {
-				let i: Int = index
-				index += 1
-				return self[i]
-			}
-			return nil
-		}
+    var i = indices.makeIterator()
+    return AnyIterator { i.next().map { self[$0] } }
 	}
 	
 	/**
diff --git a/Sources/SortedMultiDictionary.swift b/Sources/SortedMultiDictionary.swift
index adcd624..9d15c7d 100644
--- a/Sources/SortedMultiDictionary.swift
+++ b/Sources/SortedMultiDictionary.swift
@@ -89,20 +89,12 @@ public struct SortedMultiDictionary<Key: Comparable, Value>: Probable, Collectio
     
     /// Retrieves an Array of the key values in order.
     public var keys: [Key] {
-        var s = [Key]()
-        for x in self {
-            s.append(x.key)
-        }
-        return s
+        return map { $0.key }
     }
     
     /// Retrieves an Array of the values that are sorted based
     public var values: [Value] {
-        var s = [Value]()
-        for x in self {
-            s.append(x.value!)
-        }
-        return s
+        return flatMap { $0.value }
     }
     
     /// Initializer.
@@ -128,15 +120,8 @@ public struct SortedMultiDictionary<Key: Comparable, Value>: Probable, Collectio
     }
     
     public func makeIterator() -> SortedMultiDictionary.Iterator {
-        var index = startIndex
-        return AnyIterator {
-            if index < self.endIndex {
-                let i: Int = index
-                index += 1
-                return self[i]
-            }
-            return nil
-        }
+        var i = indices.makeIterator()
+        return AnyIterator { i.next().map { self[$0] } }
     }
     
     /**
diff --git a/Sources/SortedMultiSet.swift b/Sources/SortedMultiSet.swift
index 8f8eee9..37ba217 100644
--- a/Sources/SortedMultiSet.swift
+++ b/Sources/SortedMultiSet.swift
@@ -72,15 +72,7 @@ public struct SortedMultiSet<T: Comparable>: Probable, Collection, Equatable, Cu
 		- returns:	String
 	*/
 	public var description: String {
-		var output = "["
-		let l = count - 1
-		for i in 0..<count {
-			output += "\(self[i])"
-			if i != l {
-				output += ", "
-			}
-		}
-		return output + "]"
+    return "[" + map { "\($0)" }.joined(separator: ", ") + "]"
 	}
 
 	/**
@@ -165,15 +157,8 @@ public struct SortedMultiSet<T: Comparable>: Probable, Collection, Equatable, Cu
 	//	:returns:	SortedMultiSet.Generator
 	//	
 	public func makeIterator() -> SortedMultiSet.Iterator {
-        var index = startIndex
-        return AnyIterator {
-            if index < self.endIndex {
-                let i = index
-                index += 1
-                return self[i]
-            }
-            return nil
-        }
+        var i = indices.makeIterator()
+        return AnyIterator { i.next().map { self[$0] } }
 	}
 
     /**
diff --git a/Sources/SortedSet.swift b/Sources/SortedSet.swift
index 0e4183a..c39d336 100644
--- a/Sources/SortedSet.swift
+++ b/Sources/SortedSet.swift
@@ -58,11 +58,7 @@ public struct SortedSet<T: Comparable>: Probable, Collection, Equatable, CustomS
 		:name:	asArray
 	*/
 	public var asArray: [Element] {
-		var a = [Element]()
-		for x in self {
-			a.append(x)
-		}
-		return a
+    return map { $0 }
 	}
 	
 	/**
@@ -72,15 +68,7 @@ public struct SortedSet<T: Comparable>: Probable, Collection, Equatable, CustomS
 		- returns:	String
 	*/
 	public var description: String {
-		var output = "["
-		let l = count - 1
-		for i in 0..<count {
-			output += "\(self[i])"
-			if i != l {
-				output += ", "
-			}
-		}
-		return output + "]"
+    return "[" + map { "\($0)" }.joined(separator: ",") + "]"
 	}
 
 	/**
@@ -105,15 +93,6 @@ public struct SortedSet<T: Comparable>: Probable, Collection, Equatable, CustomS
 		return tree.last?.value
 	}
 
-	/**
-		:name:	isEmpty
-		:description:	A boolean of whether the RedBlackTree is empty.
-		- returns:	Bool
-	*/
-	public var isEmpty: Bool {
-		return 0 == count
-	}
-
 	/**
 		:name:	startIndex
 		:description:	Conforms to the Collection Protocol.
@@ -158,15 +137,8 @@ public struct SortedSet<T: Comparable>: Probable, Collection, Equatable, CustomS
 	}
 
 	public func makeIterator() -> SortedSet.Iterator {
-        var index = startIndex
-        return AnyIterator {
-            if index < self.endIndex {
-                let i = index
-                index += 1
-                return self[i]
-            }
-            return nil
-        }
+      var i = indices.makeIterator()
+      return AnyIterator { i.next().map { self[$0] } }
 	}
 
 	/**
@@ -283,7 +255,7 @@ public struct SortedSet<T: Comparable>: Probable, Collection, Equatable, CustomS
 	*/
 	mutating public func insert(_ elements: [Element]) {
 		for x in elements {
-            tree.insert(value: x, for: x)
+      tree.insert(value: x, for: x)
 		}
 		count = tree.count
 	}