# ==(_:_:) Returns a Boolean value indicating whether the left-hand-side argument is `nil`. ``` static func == (lhs: borrowing Wrapped?, rhs: _OptionalNilComparisonType) -> Bool ``` ## Parameters `lhs` A value to compare to `nil`. `rhs` A `nil` literal. ## Discussion You can use this equal-to operator (`==`) to test whether an optional instance is `nil` even when the wrapped value’s type does not conform to the `Equatable` protocol. The following example declares the `stream` variable as an optional instance of a hypothetical `DataStream` type. Although `DataStream` is not an `Equatable` type, this operator allows checking whether `stream` is `nil`. ``` var stream: DataStream? = nil if stream == nil { print("No data stream is configured.") } // Prints "No data stream is configured." ``` --- 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)