* `tuple_indexing` - Allows use of tuple indexing (expressions like `expr.0`)
+* `associated_types` - Allows type aliases in traits. Experimental.
+
If a feature is promoted to a language feature, then all existing programs will
start to receive compilation warnings about #[feature] directives which enabled
the new feature (because the directive is no longer necessary). However, if
they exist to support interoperability with foreign code,
and writing performance-critical or low-level functions.
-The standard library contains addtional 'smart pointer' types beyond references
+The standard library contains additional 'smart pointer' types beyond references
and raw pointers.
### Function types