# callAsFunction(value:) Presents the immersive space that handles the type of the presented value. ``` @discardableResult @MainActor func callAsFunction(value: D) async -> OpenImmersiveSpaceAction.Result where D : Decodable, D : Encodable, D : Hashable ``` ## Parameters `value` The value to present. ## Discussion Don’t call this method directly. SwiftUI calls it when you call the [`openImmersiveSpace`](/documentation/SwiftUI/EnvironmentValues/openImmersiveSpace) action with a value: ``` await openImmersiveSpace(value: planet.ID) ``` For information about how Swift uses the `callAsFunction()` method to simplify call site syntax, see [Methods with Special Names](https://docs.swift.org/swift-book/documentation/the-swift-programming-language/declarations/#Methods-with-Special-Names) in *The Swift Programming Language*. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)