---
title: "ComposableOpenTarget"
description: "The [Composable] declares that it doesn't expect a particular applier. See [ComposableTarget] for
more details on what appliers a [Composable] function expects.

In a [Composable] function, all the open composable appliers with the same applier index must
have the same name.. [CompositionLocalProvider], for example, can use [ComposableOpenTarget] to
declare that its content parameter must have the same applier as it receives, since it calls the
content parameter directly, but it could be any applier. [ComposableOpenTarget], in this way,
works like an open type parameter for the type of applier used by the implied composer parameter.

Th [ComposableOpenTarget] is unlikely to be required explicitly as it is inferred automatically
by the Compose compiler plugin. See [ComposableTarget] for more details on how attributes are
inferred."
type: "class"
---

<div class='type'>Class</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>


```kotlin
@Target(
    AnnotationTarget.FUNCTION,
    AnnotationTarget.PROPERTY_GETTER,
    AnnotationTarget.TYPE,
    AnnotationTarget.TYPE_PARAMETER,
)
public annotation class ComposableOpenTarget(val index: Int)
```


The `Composable` declares that it doesn't expect a particular applier. See `ComposableTarget` for
more details on what appliers a `Composable` function expects.

In a `Composable` function, all the open composable appliers with the same applier index must
have the same name.. `CompositionLocalProvider`, for example, can use `ComposableOpenTarget` to
declare that its content parameter must have the same applier as it receives, since it calls the
content parameter directly, but it could be any applier. `ComposableOpenTarget`, in this way,
works like an open type parameter for the type of applier used by the implied composer parameter.

Th `ComposableOpenTarget` is unlikely to be required explicitly as it is inferred automatically
by the Compose compiler plugin. See `ComposableTarget` for more details on how attributes are
inferred.

#### Parameters

| | |
| --- | --- |
| index | The index of the open applier parameter. All open appliers with the same non-negative index in the same declaration must have the same name. All negative indexes are considered anonymous and can match any applier. If the `index` is only used once in a declaration it can also match any applier but it is recommended to use a negative index instead or just leave the annotation off as a missing annotation is equivalent to an anonymous applier. |