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/*
* 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
/**
* Stable is used to communicate some guarantees to the compose compiler about how a certain type
* or function will behave.
*
* When applied to a class or an interface, [Stable] indicates that the following must be true:
*
* 1) The result of [equals] will always return the same result for the same two instances.
* 2) When a public property of the type changes, composition will be notified.
* 3) All public property types are stable.
*
* When applied to a function or a property, the [Stable] annotation indicates that the function
* will return the same result if the same parameters are passed in. This is only meaningful if
* the parameters and results are themselves [Stable], [Immutable], or primitive.
*
* The invariants that this annotation implies are used for optimizations by the compose compiler,
* and have undefined behavior if the above assumptions are not met. As a result, one should not
* use this annotation unless they are certain that these conditions are satisfied.
*
* @see Immutable
* @see StableMarker
*/
@MustBeDocumented
@Target(
AnnotationTarget.CLASS,
AnnotationTarget.FUNCTION,
AnnotationTarget.PROPERTY_GETTER,
AnnotationTarget.PROPERTY
)
@Retention(AnnotationRetention.BINARY)
@StableMarker
annotation class Stable