384     pub struct OnceCell<T> {  struct
390     // `&unsync::OnceCell` to sneak a `T` through `catch_unwind`,
393     impl<T: RefUnwindSafe + UnwindSafe> RefUnwindSafe for OnceCell<T> {}  implementation
394     impl<T: UnwindSafe> UnwindSafe for OnceCell<T> {}  implementation
396     impl<T> Default for OnceCell<T> {  implementation
402     impl<T: fmt::Debug> fmt::Debug for OnceCell<T> {  implementation
411     impl<T: Clone> Clone for OnceCell<T> {  implementation
427     impl<T: PartialEq> PartialEq for OnceCell<T> {  implementation
433     impl<T: Eq> Eq for OnceCell<T> {}  implementation
435     impl<T> From<T> for OnceCell<T> {  implementation
441     impl<T> OnceCell<T> {  impl
869     pub struct OnceCell<T>(Imp<T>);  struct
871     impl<T> Default for OnceCell<T> {  implementation
877     impl<T: fmt::Debug> fmt::Debug for OnceCell<T> {  implementation
886     impl<T: Clone> Clone for OnceCell<T> {  implementation
902     impl<T> From<T> for OnceCell<T> {  implementation
908     impl<T: PartialEq> PartialEq for OnceCell<T> {  implementation
914     impl<T: Eq> Eq for OnceCell<T> {}  implementation
916     impl<T> OnceCell<T> {  impl