| /* |
| * Copyright 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package androidx.compose.runtime |
| |
| /** |
| * [Immutable] can be used to mark class as producing immutable instances. The immutability of the |
| * class is not validated and is a promise by the type that all publicly accessible properties |
| * and fields will not change after the instance is constructed. This is a stronger promise than |
| * `val` as it promises that the value will never change not only that values cannot be changed |
| * through a setter. |
| * |
| * [Immutable] is used by composition which enables composition optimizations that can be |
| * performed based on the assumption that values read from the type will not change. See |
| * [StableMarker] for additional details. |
| * |
| * `data` classes that only contain `val` properties that do not have custom getters can safely |
| * be marked as [Immutable] if the types of properties are either primitive types or also |
| * [Immutable]: |
| * |
| * @sample androidx.compose.runtime.samples.simpleImmutableClass |
| * |
| * Marking `Person` immutable allows calls the `PersonView` [Composable] function to be skipped if |
| * it is the same `person` as it was during the last composition. |
| * |
| * @see StableMarker |
| */ |
| @MustBeDocumented |
| @Target(AnnotationTarget.CLASS) |
| @Retention(AnnotationRetention.BINARY) |
| @StableMarker |
| annotation class Immutable |