Make the project compile with Swift 5

Bond.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name         = "Bond"
-  s.version      = "7.2.0"
+  s.version      = "7.2.1"
   s.summary      = "A Swift binding framework"
 
   s.description  = <<-DESC
@@ -21,7 +21,7 @@ Pod::Spec.new do |s|
   s.ios.deployment_target = "8.0"
   s.osx.deployment_target = "10.11"
   s.tvos.deployment_target = "9.0"
-  s.source       = { :git => "https://github.com/SwiftBond/Bond.git", :tag => "7.2.0" }
+  s.source       = { :git => "https://github.com/SwiftBond/Bond.git", :tag => "7.2.1" }
   s.source_files  = "Sources/**/*.{h,m,swift}", "Supporting Files/Bond.h"
   s.ios.exclude_files = "Sources/Bond/AppKit"
   s.tvos.exclude_files = "Sources/Bond/AppKit"

Sources/Bond/Data Structures/TreeArray.swift

@@ -27,7 +27,7 @@ import Foundation
 public protocol TreeArrayProtocol: ArrayBasedTreeNode {
     associatedtype ChildValue
     init()
-    subscript(indexPath: IndexPath) -> ChildNode { get set }
+    subscript(indexPath: Index) -> ChildNode { get set }
 }
 
 /// A tree array represents a valueless root node of a tree structure where children are of TreeNode<ChileValue> type.

Sources/Bond/Observable Collections/ChangesetContainer.swift

@@ -98,7 +98,7 @@ extension MutableChangesetContainerProtocol {
     }
 }
 
-extension ChangesetContainerProtocol where Changeset.Collection: Collection {
+extension ChangesetContainerProtocol where Changeset.Collection: Swift.Collection {
 
     /// Returns `true` if underlying collection is empty, `false` otherwise.
     public var isEmpty: Bool {
@@ -118,7 +118,7 @@ extension ChangesetContainerProtocol where Changeset.Collection: Collection {
     }
 }
 
-extension ChangesetContainerProtocol where Changeset.Collection: Collection, Changeset.Collection.Index == Int {
+extension ChangesetContainerProtocol where Changeset.Collection: Swift.Collection, Changeset.Collection.Index == Int {
 
     /// Underlying array.
     public var array: Collection {

Sources/Bond/Observable Collections/OrderedCollectionDiff+IndexPath+Patch.swift

@@ -145,8 +145,9 @@ extension OrderedCollectionDiff where Index == IndexPath {
             return AnyOrderedCollectionOperation.simulate(patch: patch.map { $0.asAnyOrderedCollectionOperation }, on: $0)
         }
 
-        let updates = zip(self.updates, updatesInFinalCollection).map { (pair) -> OrderedCollectionOperation<C.ChildNode, C.Index> in
-            return .update(at: pair.0, newElement: collection[pair.1!])
+        let zipped = zip(self.updates, updatesInFinalCollection)
+        let updates = zipped.map { (pair) -> OrderedCollectionOperation<C.ChildNode, C.Index> in
+            return .update(at: pair.0, newElement: collection[pair.1])
         }
 
         return updates + patch

Sources/Bond/Observable Collections/OrderedCollectionDiff+Strideable+Patch.swift

@@ -88,8 +88,9 @@ extension OrderedCollectionDiff where Index: Strideable {
             return AnyOrderedCollectionOperation.simulate(patch: patch.map { $0.asAnyOrderedCollectionOperation }, on: $0)
         }
 
-        let updates = zip(self.updates, updatesInFinalCollection).map { (pair) -> OrderedCollectionOperation<C.Element, C.Index> in
-            return .update(at: pair.0, newElement: collection[pair.1!])
+        let zipped = zip(self.updates, updatesInFinalCollection)
+        let updates = zipped.map { (pair) -> OrderedCollectionOperation<C.Element, C.Index> in
+            return .update(at: pair.0, newElement: collection[pair.1])
         }
 
         return updates + patch

Supporting Files/Bond-Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>7.2.0</string>
+	<string>7.2.1</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>NSPrincipalClass</key>