---
title: "callAsFunction(_:)"
framework: foundation
role: symbol
role_heading: Instance Method
path: "foundation/attributecontainer/builder/callasfunction(_:)"
---

# callAsFunction(_:)

Builds an attribute container by setting an attribute and returning a modified attribute container.

## Declaration

```swift
@preconcurrency func callAsFunction(_ value: T.Value) -> AttributeContainer where T.Value : Sendable
```

## Parameters

- `value`: The value to set on the returned attribute container.

## Return Value

Return Value An attribute container with the provided value set on the builder’s AttributedStringKey.