diff options
| -rw-r--r-- | library/core/src/option.rs | 54 |
1 files changed, 26 insertions, 28 deletions
diff --git a/library/core/src/option.rs b/library/core/src/option.rs index d457d502c25..8feebe11e97 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -1072,6 +1072,32 @@ impl<T> Option<T> { } } + /// Converts from `Option<T>` (or `&Option<T>`) to `Option<&T::Target>`. + /// + /// Leaves the original Option in-place, creating a new one with a reference + /// to the original one, additionally coercing the contents via [`Deref`]. + /// + /// # Examples + /// + /// ``` + /// let x: Option<String> = Some("hey".to_owned()); + /// assert_eq!(x.as_deref(), Some("hey")); + /// + /// let x: Option<String> = None; + /// assert_eq!(x.as_deref(), None); + /// ``` + #[stable(feature = "option_deref", since = "1.40.0")] + #[rustc_const_unstable(feature = "const_option_ext", issue = "91930")] + pub const fn as_deref(&self) -> Option<&T::Target> + where + T: ~const Deref, + { + match self.as_ref() { + Some(t) => Some(t.deref()), + None => None, + } + } + ///////////////////////////////////////////////////////////////////////// // Iterator constructors ///////////////////////////////////////////////////////////////////////// @@ -1724,34 +1750,6 @@ impl<T: Clone> Option<&mut T> { } } -impl<T: Deref> Option<T> { - /// Converts from `Option<T>` (or `&Option<T>`) to `Option<&T::Target>`. - /// - /// Leaves the original Option in-place, creating a new one with a reference - /// to the original one, additionally coercing the contents via [`Deref`]. - /// - /// # Examples - /// - /// ``` - /// let x: Option<String> = Some("hey".to_owned()); - /// assert_eq!(x.as_deref(), Some("hey")); - /// - /// let x: Option<String> = None; - /// assert_eq!(x.as_deref(), None); - /// ``` - #[stable(feature = "option_deref", since = "1.40.0")] - #[rustc_const_unstable(feature = "const_option_ext", issue = "91930")] - pub const fn as_deref(&self) -> Option<&T::Target> - where - T: ~const Deref, - { - match self.as_ref() { - Some(t) => Some(t.deref()), - None => None, - } - } -} - impl<T: DerefMut> Option<T> { /// Converts from `Option<T>` (or `&mut Option<T>`) to `Option<&mut T::Target>`. /// |