Add RegisterDisposeCallback and refine callback impl

VContainer/Assets/VContainer/Runtime/ContainerBuilder.cs

@@ -69,7 +69,7 @@ public DiagnosticsCollector Diagnostics
         }
 
         readonly List<RegistrationBuilder> registrationBuilders = new List<RegistrationBuilder>();
-        List<Action<IObjectResolver>> buildCallbacks;
+        Action<IObjectResolver> buildCallback;
         DiagnosticsCollector diagnostics;
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -83,9 +83,7 @@ public T Register<T>(T registrationBuilder) where T : RegistrationBuilder
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void RegisterBuildCallback(Action<IObjectResolver> callback)
         {
-            if (buildCallbacks == null)
-                buildCallbacks = new List<Action<IObjectResolver>>();
-            buildCallbacks.Add(callback);
+            buildCallback += callback;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -149,13 +147,7 @@ protected Registry BuildRegistry()
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         protected void EmitCallbacks(IObjectResolver container)
         {
-            if (buildCallbacks == null) return;
-
-            foreach (var callback in buildCallbacks)
-            {
-                callback.Invoke(container);
-            }
-
+            buildCallback?.Invoke(container);
             Diagnostics?.NotifyContainerBuilt(container);
         }
     }

VContainer/Assets/VContainer/Runtime/ContainerBuilderExtensions.cs

@@ -145,6 +145,11 @@ public static RegistrationBuilder RegisterFactory<TParam1, TParam2, TParam3, TPa
             Lifetime lifetime)
             => builder.Register(new FuncRegistrationBuilder(factoryFactory, typeof(Func<TParam1, TParam2, TParam3, TParam4, T>), lifetime));
 
+        public static void RegisterDisposeCallback(this IContainerBuilder builder, Action<IDisposable> callback)
+        {
+            builder.Register(container => new ActionDisposable(callback, container), Lifetime.Scoped);
+        }
+
         [Obsolete("IObjectResolver is registered by default. This method does nothing.")]
         public static void RegisterContainer(this IContainerBuilder builder)
         {

VContainer/Assets/VContainer/Runtime/Internal/ActionDisposable.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace VContainer.Internal
+{
+    struct ActionDisposable : IDisposable
+    {
+        readonly Action<IObjectResolver> callback;
+        readonly IObjectResolver container;
+
+        public ActionDisposable(Action<IObjectResolver> callback, IObjectResolver container)
+        {
+            this.callback = callback;
+            this.container = container;
+        }
+
+        public void Dispose()
+        {
+            callback.Invoke(container);
+        }
+    }
+}