also requires enabling the library feature `compiler_builtins_lib`. You can read
more about this [here][compiler-builtins-lib].
-[compiler-builtins-lib]: library-features/compiler-builtins-lib.html
+[compiler-builtins-lib]: ../library-features/compiler-builtins-lib.md
## More about the language items
- `freeze`: `libcore/marker.rs`
- `debug_trait`: `libcore/fmt/mod.rs`
- `non_zero`: `libcore/nonzero.rs`
+ - `arc`: `liballoc/sync.rs`
+ - `rc`: `liballoc/rc.rs`