diff --git a/Sources/SelectableCollectionView/Views/CollectionViewContainer.swift b/Sources/SelectableCollectionView/Views/CollectionViewContainer.swift
index 73a92d7..d7789d1 100644
--- a/Sources/SelectableCollectionView/Views/CollectionViewContainer.swift
+++ b/Sources/SelectableCollectionView/Views/CollectionViewContainer.swift
@@ -26,22 +26,26 @@ import SwiftUI
 
 import SelectableCollectionViewMacResources
 
-#warning("TODO: Rename element to ID to avoid confusion?")
-
-protocol CollectionViewContainerDelegate: NSObject {
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   menuItemsForElements elements: Set<Element>) -> [MenuItem]
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   contentForElement element: Element) -> Content?
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   didUpdateSelection selection: Set<Element>)
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   didDoubleClickSelection selection: Set<Element>)
-
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   keyDown event: NSEvent) -> Bool
-    func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                   keyUp event: NSEvent) -> Bool
+// TODO: Rename element to ID to avoid confusion?
+
+public protocol CollectionViewContainerDelegate: NSObject {
+
+    associatedtype Element: Hashable & Identifiable
+    associatedtype CellContent: View
+
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 menuItemsForElements elements: Set<Element>) -> [MenuItem]
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 contentForElement element: Element) -> CellContent?
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 didUpdateSelection selection: Set<Element>)
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 didDoubleClickSelection selection: Set<Element>)
+
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 keyDown event: NSEvent) -> Bool
+    func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, CellContent, Self>,
+                                 keyUp event: NSEvent) -> Bool
 }
 
 class CustomScrollView: NSScrollView {
@@ -64,12 +68,14 @@ class CustomScrollView: NSScrollView {
 
 }
 
-public class CollectionViewContainer<Element: Hashable, Content: View>: NSView,
-                                                                        NSCollectionViewDelegate,
-                                                                        CollectionViewInteractionDelegate,
-                                                                        NSCollectionViewDelegateFlowLayout {
+public class CollectionViewContainer<Element: Hashable, Content: View, Delegate: CollectionViewContainerDelegate>
+: NSView,
+  NSCollectionViewDelegate,
+  CollectionViewInteractionDelegate,
+  NSCollectionViewDelegateFlowLayout where Delegate.Element == Element,
+                                           Delegate.CellContent == Content {
 
-    weak var delegate: CollectionViewContainerDelegate?
+    weak var delegate: Delegate?
 
     enum Section {
         case none
diff --git a/Sources/SelectableCollectionView/Views/CollectionViewContainerHost.swift b/Sources/SelectableCollectionView/Views/CollectionViewContainerHost.swift
index 6f2128f..929f0fd 100644
--- a/Sources/SelectableCollectionView/Views/CollectionViewContainerHost.swift
+++ b/Sources/SelectableCollectionView/Views/CollectionViewContainerHost.swift
@@ -23,14 +23,18 @@
 import SwiftUI
 
 public struct CollectionViewContainerHost<Data: RandomAccessCollection,
-                                          Content: View>: NSViewRepresentable where Data.Element: Identifiable,
-                                                                                    Data.Element: Hashable,
-                                                                                    Data.Element.ID: Hashable {
+                                          Content: View>
+: NSViewRepresentable where Data.Element: Identifiable,
+                            Data.Element: Hashable,
+                            Data.Element.ID: Hashable {
 
     public typealias ID = Data.Element.ID
     public typealias Element = Data.Element
 
-    public class Coordinator: NSObject, CollectionViewContainerDelegate {
+    public final class Coordinator: NSObject, CollectionViewContainerDelegate {
+
+        public typealias Element = Data.Element
+        public typealias CellContent = Content
 
         var parent: CollectionViewContainerHost<Data, Content>
         var collectionViewLayoutHash: Int = 0
@@ -39,50 +43,36 @@ public struct CollectionViewContainerHost<Data: RandomAccessCollection,
             self.parent = parent
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       menuItemsForElements elements: Set<Element>) -> [MenuItem] where Element : Hashable, Content : View {
-            guard let elements = elements as? Set<Data.Element> else {
-                return []
-            }
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            menuItemsForElements elements: Set<Element>) -> [MenuItem] {
             let ids = Set(elements.map { $0.id })
             return parent.contextMenu(ids)
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       contentForElement element: Element) -> Content? where Element : Hashable, Content : View {
-#warning("TODO: These guards shouldn't be necessary?")
-            guard let element = element as? Data.Element,
-                  let content = parent.itemContent(element) as? Content else {
-                return nil
-            }
-            return content
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            contentForElement element: Element) -> Content? {
+            return parent.itemContent(element)
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       didUpdateSelection selection: Set<Element>) where Element : Hashable, Content : View {
-            guard let selection = selection as? Set<Data.Element> else {
-                return
-            }
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            didUpdateSelection selection: Set<Element>) {
             let ids = Set(selection.map { $0.id })
             parent.selection.wrappedValue = ids
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       didDoubleClickSelection selection: Set<Element>) where Element : Hashable, Content : View {
-            guard let selection = selection as? Set<Data.Element> else {
-                return
-            }
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            didDoubleClickSelection selection: Set<Element>) {
             let ids = Set(selection.map { $0.id })
             parent.primaryAction(ids)
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       keyDown event: NSEvent) -> Bool where Element : Hashable, Content : View {
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            keyDown event: NSEvent) -> Bool {
             return parent.keyDown(event)
         }
 
-        func collectionViewContainer<Element, Content>(_ collectionViewContainer: CollectionViewContainer<Element, Content>,
-                                                       keyUp event: NSEvent) -> Bool where Element : Hashable, Content : View {
+        public func collectionViewContainer(_ collectionViewContainer: CollectionViewContainer<Element, Content, Coordinator>,
+                                            keyUp event: NSEvent) -> Bool {
             return parent.keyUp(event)
         }
 
@@ -119,15 +109,14 @@ public struct CollectionViewContainerHost<Data: RandomAccessCollection,
         return Coordinator(self)
     }
 
-    public func makeNSView(context: Context) -> CollectionViewContainer<Element, Content> {
-        let collectionView = CollectionViewContainer<Element, Content>(layout: layout.makeLayout())
+    public func makeNSView(context: Context) -> CollectionViewContainer<Element, Content, Coordinator> {
+        let collectionView = CollectionViewContainer<Element, Content, Coordinator>(layout: layout.makeLayout())
         collectionView.delegate = context.coordinator
         return collectionView
     }
 
-    public func updateNSView(_ collectionView: CollectionViewContainer<Element, Content>, context: Context) {
+    public func updateNSView(_ collectionView: CollectionViewContainer<Element, Content, Coordinator>, context: Context) {
         context.coordinator.parent = self
-#warning("TODO: We shouldn't need to copy this into an array?")
         let selectedElements = items.filter { selection.wrappedValue.contains($0.id) }
         collectionView.update(Array(items), selection: Set(selectedElements))
 
@@ -137,7 +126,6 @@ public struct CollectionViewContainerHost<Data: RandomAccessCollection,
             context.coordinator.collectionViewLayoutHash = layout.hashValue
         }
     }
-
 }
 
 #endif