Add Id::cast

madsmtm · Dec 21, 2021 · b276169 · b276169
1 parent 3d0e46b
commit b276169
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Showing 3 changed files with 13 additions and 7 deletions.
diff --git a/objc2-foundation/src/object.rs b/objc2-foundation/src/object.rs
@@ -41,8 +41,7 @@ object!(unsafe pub struct NSObject);
 
 impl NSObject {
     pub fn new() -> Id<Self, Owned> {
-        unsafe { ffi::NSObject::new().unwrap() };
-        todo!("unsafe Id::cast")
+        unsafe { ffi::NSObject::new().unwrap().cast().into_owned() }
     }
 }
 

diff --git a/objc2-foundation/src/string.rs b/objc2-foundation/src/string.rs
@@ -86,17 +86,17 @@ pub unsafe trait INSString: INSObject {
 
     fn from_str(string: &str) -> Id<Self, Shared> {
         let bytes = string.as_ptr() as *const c_void;
-        unsafe {
-            let obj = ffi::NSString::alloc().unwrap();
+        let obj = unsafe { ffi::NSString::alloc().unwrap() };
+        let obj = unsafe {
             ffi::NSString::initWithBytes_length_encoding_(
                 obj,
                 bytes,
                 string.len(),
                 ffi::NSUTF8StringEncoding,
             )
-            .unwrap();
-            todo!("unsafe Id::cast")
-        }
+            .unwrap()
+        };
+        unsafe { obj.cast().into_shared() }
     }
 }
 

diff --git a/objc2/src/rc/id.rs b/objc2/src/rc/id.rs
@@ -346,6 +346,13 @@ impl<T: Message> Id<T, Unknown> {
         pool.__verify_is_inner();
         self.autorelease_inner()
     }
+
+    #[inline]
+    // TODO: Can we make this safe?
+    pub unsafe fn cast<U: Message>(self) -> Id<U, Unknown> {
+        let ptr = ManuallyDrop::new(self).ptr.cast();
+        unsafe { Id::new(ptr) }
+    }
 }
 
 impl<T: Message> From<Id<T, Owned>> for Id<T, Shared> {