1 A lang item was redefined.
3 Erroneous code example:
6 #![feature(lang_items)]
9 struct Foo; // error: duplicate lang item found: `owned_box`
12 Lang items are already implemented in the standard library. Unless you are
13 writing a free-standing application (e.g., a kernel), you do not need to provide
16 You can build a free-standing crate by adding `#![no_std]` to the crate
19 ```ignore (only-for-syntax-highlight)
23 See also the [unstable book][1].
25 [1]: https://doc.rust-lang.org/unstable-book/language-features/lang-items.html#writing-an-executable-without-stdlib