Merge pull request #137 from dtolnay/cast

Force turbofish on all calls of .cast::<U>()
dtolnay · Jan 30, 2021 · 3626541 · 3626541
2 parents 3723acd + 3fdef75
commit 3626541
Showing 1 changed file with 12 additions and 3 deletions.
diff --git a/src/ptr.rs b/src/ptr.rs
@@ -23,7 +23,7 @@ impl<T> Own<T> {
         }
     }
 
-    pub fn cast<U>(self) -> Own<U> {
+    pub fn cast<U: CastTo>(self) -> Own<U::Target> {
         Own {
             ptr: self.ptr.cast(),
         }
@@ -69,7 +69,7 @@ impl<'a, T> Ref<'a, T> {
         }
     }
 
-    pub fn cast<U>(self) -> Ref<'a, U> {
+    pub fn cast<U: CastTo>(self) -> Ref<'a, U::Target> {
         Ref {
             ptr: self.ptr.cast(),
             lifetime: PhantomData,
@@ -102,7 +102,7 @@ impl<'a, T> Mut<'a, T> {
         }
     }
 
-    pub fn cast<U>(self) -> Mut<'a, U> {
+    pub fn cast<U: CastTo>(self) -> Mut<'a, U::Target> {
         Mut {
             ptr: self.ptr.cast(),
             lifetime: PhantomData,
@@ -124,3 +124,12 @@ impl<'a, T> Mut<'a, T> {
         self.ptr.as_ptr().read()
     }
 }
+
+// Force turbofish on all calls of `.cast::<U>()`.
+pub trait CastTo {
+    type Target;
+}
+
+impl<T> CastTo for T {
+    type Target = T;
+}