324     pub struct OnceCell<T> {  struct
330     // `&unsync::OnceCell` to sneak a `T` through `catch_unwind`,
334     impl<T: RefUnwindSafe + UnwindSafe> RefUnwindSafe for OnceCell<T> {}  implementation
336     impl<T: UnwindSafe> UnwindSafe for OnceCell<T> {}  implementation
338     impl<T> Default for OnceCell<T> {  implementation
344     impl<T: fmt::Debug> fmt::Debug for OnceCell<T> {  implementation
353     impl<T: Clone> Clone for OnceCell<T> {  implementation
366     impl<T: PartialEq> PartialEq for OnceCell<T> {  implementation
372     impl<T: Eq> Eq for OnceCell<T> {}  implementation
374     impl<T> From<T> for OnceCell<T> {  implementation
380     impl<T> OnceCell<T> {  implementation
699     pub struct OnceCell<T>(Imp<T>);  struct
701     impl<T> Default for OnceCell<T> {  implementation
707     impl<T: fmt::Debug> fmt::Debug for OnceCell<T> {  implementation
716     impl<T: Clone> Clone for OnceCell<T> {  implementation
729     impl<T> From<T> for OnceCell<T> {  implementation
737     impl<T: PartialEq> PartialEq for OnceCell<T> {  implementation
743     impl<T: Eq> Eq for OnceCell<T> {}  implementation
745     impl<T> OnceCell<T> {  implementation