# line() Produces the line number on which it appears. ``` @freestanding(expression) macro line() -> T where T : ExpressibleByIntegerLiteral ``` ## Overview This macro’s value can be changed by `#sourceLocation`, as described in [Line Control Statement](https://docs.swift.org/swift-book/documentation/the-swift-programming-language/statements#Line-Control-Statement) in [The Swift Programming Language](https://docs.swift.org/swift-book/). --- 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)