1 The lang attribute was used in an invalid context.
3 Erroneous code example:
6 #![feature(lang_items)]
9 fn cookie() -> ! { // error: definition of an unknown language item: `cookie`
14 The lang attribute is intended for marking special items that are built-in to
15 Rust itself. This includes special traits (like `Copy` and `Sized`) that affect
16 how the compiler behaves, as well as special functions that may be automatically
17 invoked (such as the handler for out-of-bounds accesses when indexing a slice).