rollup merge of #19520: csouth3/derefmut-unsized

emberian · emberian · commit c7d545e2f7d3 · 2014-12-05T10:07:47.000-08:00
Right now, `DerefMut` is not `for Sized?`, so you can't impl `DerefMut<T> for Foo` where `Foo` is unsized. However, there is no reason that it can't be `for Sized?`, so this pull request fixes the issue. Closes #19493.
diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs
@@ -787,7 +787,7 @@ impl<'a, Sized? T> Deref<T> for &'a mut T {
 /// }
 /// ```
 #[lang="deref_mut"]
-pub trait DerefMut<Sized? Result>: Deref<Result> {
+pub trait DerefMut<Sized? Result> for Sized? : Deref<Result> {
     /// The method called to mutably dereference a value
     fn deref_mut<'a>(&'a mut self) -> &'a mut Result;
 }

Original file line number	Diff line number	Diff line change
`@@ -787,7 +787,7 @@ impl<'a, Sized? T> Deref<T> for &'a mut T {`
`787`	`787`	`/// }`
`788`	`788`	/// ```
`789`	`789`	`#[lang="deref_mut"]`
`790`		`-pub trait DerefMut<Sized? Result>: Deref<Result> {`
	`790`	`+pub trait DerefMut<Sized? Result> for Sized? : Deref<Result> {`
`791`	`791`	`/// The method called to mutably dereference a value`
`792`	`792`	`fn deref_mut<'a>(&'a mut self) -> &'a mut Result;`
`793`	`793`	`}`