Can a computed property be `async` or `throw` errors?

Answer: Yes — since Swift 5.5, a read-only computed property can mark its getter async, throws, or both, and callers must use await / try to read it.

Code Example:

struct RemoteImage {
    let url: URL

    var data: Data {
        get async throws {
            let (data, _) = try await URLSession.shared.data(from: url)
            return data
        }
    }
}

let image = RemoteImage(url: someURL)
let bytes = try await image.data

Key Points:

• Only read-only computed properties (and subscripts) can be effectful — a property with a setter cannot.
• Use this for values that are naturally properties but need async work, such as an actor-isolated or lazily loaded value.
• If the operation takes parameters or does heavy work, a method is still clearer.