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Move Option::as_deref

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David Tolnay 2021-12-30 10:36:37 -08:00
parent bbcf09f2fb
commit 48a91a08d1
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1 changed files with 26 additions and 28 deletions
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54
library/core/src/option.rs
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@ -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>`.
///