Write docs for SyncOnceCell From and Default impl

This commit is contained in:
Michael Howell 2021-08-01 14:37:38 -07:00
parent 4e21ef2a4e
commit e0172b380d

View File

@ -87,6 +87,19 @@ impl<T: UnwindSafe> UnwindSafe for SyncOnceCell<T> {}
#[unstable(feature = "once_cell", issue = "74465")]
impl<T> Default for SyncOnceCell<T> {
/// Creates a new empty cell.
///
/// # Example
///
/// ```
/// #![feature(once_cell)]
///
/// use std::lazy::SyncOnceCell;
///
/// fn main() {
/// assert_eq!(SyncOnceCell::<()>::new(), SyncOnceCell::default());
/// }
/// ```
fn default() -> SyncOnceCell<T> {
SyncOnceCell::new()
}
@ -118,6 +131,23 @@ impl<T: Clone> Clone for SyncOnceCell<T> {
#[unstable(feature = "once_cell", issue = "74465")]
impl<T> From<T> for SyncOnceCell<T> {
/// Create a new cell with its contents set to `value`.
///
/// # Example
///
/// ```
/// #![feature(once_cell)]
///
/// use std::lazy::SyncOnceCell;
///
/// # fn main() -> Result<(), i32> {
/// let a = SyncOnceCell::from(3);
/// let b = SyncOnceCell::new();
/// b.set(3)?;
/// assert_eq!(a, b);
/// Ok(())
/// # }
/// ```
fn from(value: T) -> Self {
let cell = Self::new();
match cell.set(value) {