Auto merge of #57428 - alexreg:associated_type_bounds, r=nikomatsakis,Centril

Implementation of RFC 2289 (associated_type_bounds)

This PR implements the [`asociated_type_bounds` feature](https://github.com/rust-lang/rfcs/blob/master/text/2289-associated-type-bounds.md).

Associated type bounds are implemented in:
   - function/method arguments and return types
   - structs, enums, unions
   - associated items in traits
   - type aliases
   - type parameter defaults
   - trait objects
   - let bindings

CC @nikomatsakis @centril

1 files changed, 2 insertions, 1 deletions

diff --git a/src/libsyntax/ptr.rs b/src/libsyntax/ptr.rs
index 9afcb7c4621..d577243fb3d 100644
--- a/src/libsyntax/ptr.rs
+++ b/src/libsyntax/ptr.rs
@@ -57,7 +57,8 @@ impl<T: 'static> P<T> {
     {
         f(*self.ptr)
     }
-    /// Equivalent to and_then(|x| x)
+
+    /// Equivalent to `and_then(|x| x)`.
     pub fn into_inner(self) -> T {
         *self.ptr
     }